April 29 2026 Demo Quiz Ryian mohamed 0 Welcome to Optics 😉 Name Email 1. Prisms Which of the following statements regarding the Prentice position is least likely? The angle of incidence equals the angle of emergence Glass prisms are traditionally held in the prentice position The deviation of light is greater in the Prentice position than in the position of minimum deviation The incident ray is normal to one surface of the prism None 2. Imaging In fluorescein fungus imaging which colour is the excitation filter? Red Yellow Green Blue None 3. Prescriptions Which test is commonly used to measure the amplitude of accommodation? Bagolini striated lenses Push-up test Maddox rod test Worth 4-dot test None 4. Calculations Transpose the -4.00 DS/ -3.00 DC X 45 into positive cylinder notation? −5.50 DS/ +3.00 DCx45 −7.00 DS/ +3.00 DCx45 −5.50 DS/ +3.00 DCx135 −7.00 DS/ +3.00 DCx135 None 5. Calculations What is the optical power (D) of a convex spherical lens with a focal length of 25 cm? -4.00D +2.50D -2.50D +4.00D None 1 2 3 4 5 Time's up April 15 2025 Histopathology Ryian mohamed 0 1. Cornea Which layer of the cornea contains keratocytes? Epithelium Bowman's layer Stroma Descemet’s membrane Endothelium None 2. Retina The internal limiting membrane of the retina is formed by: Müller cell footplates Astrocytes Photoreceptor nuclei Retinal pigment epithelium Ganglion cells None 3. Retina Drusen are histopathological features seen in: Diabetic retinopathy Retinitis pigmentosa Age-related macular degeneration Uveitis Retinoblastoma None 4. Cornea The primary site of lesion in keratoconus is: Epithelium Bowman's layer Stroma Descemet's membrane Endothelium None 5. Pathology Rosette formations on histopathology are characteristic of: Retinoblastoma Conjunctival lymphoma Orbital cellulitis Choroidal nevus None 6. Cornea Which structure is acellular and acts as the basement membrane for the corneal endothelium? Stroma Bowman's layer Descemet's membrane Bruch’s membrane Internal limiting membrane None 7. Pathology Fuchs endothelial dystrophy primarily affects which corneal layer? Epithelium Stroma Endothelium Bowman's layer Limbus None 8. Pathology Psammoma bodies may be seen in histology of which orbital tumor? Cavernous hemangioma Optic nerve glioma Schwannoma Meningioma Rhabdomyosarcoma None 9. Eyelids Which type of gland is the Meibomian gland classified as? Apocrine Sebaceous Eccrine Endocrine Mucous None 10. Retina Which retinal layer contains the nuclei of photoreceptor cells? Inner nuclear layer Outer nuclear layer Ganglion cell layer Outer plexiform layer Retinal pigment epithelium None Time's up March 18 2025 Optics Ryian mohamed 0 Welcome to Optics 😉 Name Email 1. Please select your category: Please select your answer Properties of Light Prescriptions Spherical Lenses Aberrations Refractive Surgery Lasers Prisms Calculations Mirrors Retinal Surgery Cataract Surgery Jokes Refraction by the Eye Clinical Imaging Astigmatism Instruments Visual Function Low Vision Aids 2. Calculations What is the optical power (D) of a convex spherical lens with a focal length of 25 cm? +4.00D -2.50D +2.50D -4.00D None 3. Calculations Transpose the -4.00 DS/ -3.00 DC X 45 into positive cylinder notation? −7.00 DS/ +3.00 DCx135 −7.00 DS/ +3.00 DCx45 −5.50 DS/ +3.00 DCx45 −5.50 DS/ +3.00 DCx135 None 4. Calculations A hypermetrope whose glasses contain +5.00 DS lenses wants to wear contact lenses. What is the dioptric power of the contact lens that he would require? (Back vertex distance = 15 mm) - 5.0 dioptres + 5.8 dioptres +4.5 dioptres + 5.4 dioptres None 5. Calculations A crown glass prism in air has an apical angle of 4 degrees. What will the approximate angle of deviation be in the position of minimum deviation? 2 degrees 16 degrees 4 degrees 8 degrees None 6. Calculations A glass prism (refractive index 1.5) of 20 prism diopters deviates an incident of ray of light through? 20 degrees 5 degrees 10 degrees 40 degrees None 7. Calculations The spherical equivalent of a lens with power +3.00DS/-2.00 DC is? -0.50 DS +2.00 DS -1.00 DS +1.00 DS None 8. Calculations Transpose +2.00 DS/ -1.00 DC x 180 to the base curve -2.00 D? +4.00 DS/ (-2.00 DC x 90/-3.00 DC x 180) +4.00 DS/ (-2.00 DC x 90/+1.00 DC x 180) +4.00 DS/ (-3.00 DC x 90/-3.00 DC x 180) +4.00 DS/ (-2.00 DC x 90/-1.00 DC x 180) None 9. Calculations What is the magnification of a loupe of power +16 diopters? x 4 x 64 x 8 x 32 None 10. Calculations An eye has axial length 23.0mm, with average keratometry readings of 42 diopters. Using the SRK formula (constant 118.9), aiming for emmetropia, the calculated power of an intraocular lens implant would be: 24.30 D 23.60 D 23.30 D 24.60 D None 11. Calculations What is the dioptric lens power of simple magnifying glass (loupe) with a magnification of 2.5x? 4 dioptres 10 dioptres 2.5 dioptres 25 dioptres None 12. Calculations What is the accommodative power required for a myope with a -1.5 dioptre prescription to read unaided at 25 cm? 7 dioptre 5.5 dioptre 1 dioptre 2.5 dioptre None 13. Calculations What magnitude of accommodation will be required for a hypermetropic patient within +2 dioptre prescription to read unaided at 20cm? 7 dioptres 5 dioptres 10 dioptres 3 dioptres None 14. Calculations A patient's prescription is +2.00 DS/ -1.00 DC axis 180. What is the topic transposition of this to the base curve -4.00 D? +1.00 DS/ (+1.00 DC x 90/-5.00 DC x 180) +6.00 DS/ (-4.00 DC x 90/-5.00 DC x 180) +1.00 DS/ (-5.00 DC x 180/+1.00 DC x 90) +6.00 DS/ (-4.00 DC x 180/-1.00 DC x 90) None 15. Calculations What is the degree of magnification when viewing the funds of a patient with 10 dioptres of myopia with a direct ophthalmoscope? x 17.5 x 15 x 12.5 x 2.5 None 16. Calculations What is the lens to object working distance of a simple magnifying glass of 2.5 x magnifications? 10 cm 2.5 cm 20 cm 5 cm None 17. Calculations Which of the following transpositions is incorrect? +4.50/ -2.25 x 140 = +2.25/ +2.25 x 50 -3.75/ -1.75 x 80 = -5.50/ +1.75 x 170 +2.00/ -3.25 x 20 = +1.25/ +3.25 x 110 -1.75/ -1.25 x 60 = -3.00/ +1.25 x 150 None 18. Calculations A +4.00D spectacle lens is decentered 5 mm nasally. What type of prism effect is induced? 2Δ Base In 2Δ Base Up 2Δ Base Out No prism is induced None 19. Calculations What is the tube length of an astronomical telescope with a +4.00D objective lens and a +10.00D eyepiece lens 15 cm 30 cm 35 cm 20 cm None 20. Calculations What is the prismatic effect (prism dioptres) of a 4 dioptre lens that has been decanted by 30 mm? 30 12 0.75 120 None 21. Calculations An object is placed 50cm in front of a concave spherical mirror with a radius of curvature of 2.0m. What image is produced? Virtual, enlarged Real, diminished Virtual, diminished Real, enlarged None 22. Calculations What is the Brewster angle when light travels from air to glass (n= 1.50)? 65.7 41.8 56.3 47.6 None 23. Calculations How much does a 15Δ prism bend light, in degrees? 12.4 degrees 7.5 degrees 15 degrees 8.53 degrees None 24. Calculations What is the critical angle for light travelling from glass (n=1.50) to air? 65.7 degrees 47.6 degrees 56.7 degrees 41.8 degrees None 25. Calculations Convert the following spectacle prescription from plus-cylinder to minus-cylinder notation: +2.00 / +1.50 × 90 +0.50 / -1.50 × 180 +3.50 / -1.50 × 180 +2.00 / -1.50 × 180 +3.50 / -1.50 × 90 None 26. Calculations If a cornea has an anterior radius of curvature of 7.7 mm, a posterior radius of curvature of 6.8 mm, and a centre of thickness of 0.5 mm, what will its dioptric power be if it is submerged in water? Assume index of refraction of water =1.333; index of refraction of cornea = 1.376; index of refraction of aqueous = 1.336 -5.89 D -0.30 D +32.00 D +37.60 D None 27. Calculations A cyclopegic refraction is performed for on a non verbal, adult patient at a testing distance of 67 cm. The results for the right eye is as follows: +3D share neutralises the reflex when the streak is horizontal (180 degrees); +4D sphere neutralises the reflex when the streak is vertical ( 90 degrees). What is the refraction of the right eye? +1.50 (sphere) + 1.00 x90 +3.00 (sphere) + 1.00 x90 +1.50 (sphere) - 1.00 x90 +3.00 (sphere) - 1.00 x90 None 28. Calculations During cataract surgery on a patient with an eye of axial length of 23 mm, it becomes necessary to change the IOL type. The A constant for the original IOL is 118.4 and will give a bower of 21.5 dioptres. The A constant for the new IOL is 117.4. What is the power of the new IOL? 21.0 dioptres 22.5 dioptres 20.5 dioptres 22.0 dioptres None 29. Calculations An object is placed 50cm in front of a concave spherical mirror with a radius of curvature of 2.0m. What is the transverse magnification of the image? x2 x1 x3 x4 None 30. Calculations At 20 feet, the smallest letters that a child;d can read is the 20/60 line. You have the child walk towards the eye chart. How far does she walk before she can see the 20/20 line? 15 feet 13 feet 7 feet 5 feet None 31. Calculations What is the maximum amplitude of accommodation of an emmetropic patient with a near point of 20 cm? 10 dioptres 2 dioptres 5 dioptres 8 dioptres None 32. Calculations Using this instrument with a +13D lens where is the image 0.08 cm behind the lens 0.08 cm in front of the lens 8 cm in front of the lens 8 cm behind the lens None 33. Calculations An object is placed 50cm in front of a concave spherical mirror with a radius of curvature of 2.0m. What is the power of the mirror? +1.00 -2.00 -1.00 +2.00 None 34. Calculations If a 10 dioptre concave lens is decentered by 2cm temporally, this will result in a: 5 prism dioptre base-in prism 20 prism dioptre base-out prism 20 prism dioptre base-in prism 5 prism dioptre base-out prism None 35. Calculations What is the spherical equivalent of -3.50/+1.50 axis 70? -5.00 DS -2.00/-1.50 axis 110 -2.75 DS -2.00 DS None 36. Calculations During cataract surgery a complication occurs and the decision is made to place the intraocular lens (IOL) in sulcus. A 23.5 diopter IOOL has been planned for placement in the capsular bag. Which of the following lens powers is most appropriate for placement in the sulcus? 24.5 dioptre 21.50 dioptre 22.50 dioptre 25.5 dioptre None 37. Mirrors Which type of mirror is commonly used in car rearview mirrors? Plane mirror Parabolic mirror Convex mirror Concave mirror None 38. Mirrors What optical principle allows a kaleidoscope to form symmetrical patterns? Chromatic aberration Diffraction Total internal reflection Dispersion None 39. Mirrors The object lies outside the centre of curvature of a concave mirror. How is the image formed by the mirror best best described? Real inverted diminished Real inverted enlarged Virtual erect diminished Virtual erect enlarged None 40. Mirrors How does a two-way mirror work? It reflects all light from both sides equally. It transmits light in one direction while reflecting most light from the other. It refracts light instead of reflecting it. It acts as a polarizer, allowing only certain wavelengths through. None 41. Mirrors An object is placed between the center of curvature (C) and the focal point (F) of a concave mirror. What will be the characteristics of the image formed? Real, inverted, and enlarged Virtual, erect, and enlarged Real, inverted, and diminished No image is formed None 42. Mirrors When an object is placed at the focal point (F) of a concave mirror, what is the most likely outcome? A real, erect, and same-sized image is formed A virtual, erect, and diminished image is formed. A real, inverted, and magnified image is formed. No image is formed because the reflected rays are parallel. None 43. Mirrors Which of the following statements is true about the image formed by a concave mirror when the object is placed between the focal point (F) and the mirror? The image is virtual, erect, and magnified No image is formed because light rays do not reflect. The image is real, erect, and the same size as the object. The image is real, inverted, and diminished None 44. Mirrors An object is placed beyond the center of curvature (C) of a concave mirror. What will be the characteristics of the image formed? Real, inverted, and diminished No image is formed Virtual, erect, and magnified Real, erect, and enlarged None 45. Mirrors The image formed by a convex mirror is least likely to be? Lateral Inverted Diminished Virtual Erect None 46. Mirrors Which of the following is least likely to describe the image formed when an object is placed between the focal point (F) and the mirror in a concave mirror? Inverted Enlarged Virtual Erect None 47. Mirrors Which of the following is most likely a correct rule when constructing ray diagrams for a concave mirror? A ray traveling parallel to the principal axis reflects through the focal point (F). All of the above. A ray passing through the focal point (F) reflects parallel to the principal axis. A ray passing through the center of curvature (C) reflects back along the same path. None 48. Mirrors An object located between the centre of curvature and the principle focus of a concave mirror is most likely? Erect Virtual Diminished Real None 49. Mirrors Which of the following is least likely to describe the image formed when an object is placed beyond the center of curvature (C) in a concave mirror? Diminished Magnified Inverted Real None 50. Aberrations Which optical aberration is most affected when a lens is tilted? Coma Chromatic aberration Spherical aberration Pincushion distortion None 51. Aberrations Which statement about mydriasis is least likely? There is decreased diffraction of light There is an increase in spherical aberration There is an increase in the Stiles-Crawford effect There is an increased depth of field None 52. Aberrations Which lens material has the lowest chromatic aberration? High-index plastic Polycarbonate Trivex Crown Glass None 53. Aberrations Which type of optical aberration is characterized by different focal points for different wavelengths of light? Chromatic aberration Coma Spherical aberration Astigmatism None 54. Aberrations Which of the following statements about dispersion and chromatic aberration is most likely? Blue-blocking and red-blocking sunglasses improve sharpness by eliminating part of the chromatic interval, thereby reducing chromatic abberation In the human eye, blue rays focus behind red rays Red print appears nearer than blue print when both are displayed against a black background Image sharpness is improved by chromatic aberration in the eyes of the patients with achromatopsia None 55. Aberrations Coma aberration is most commonly seen in which type of optical system? Cylindrical lenses High-index lenses On-axis point sources Off-axis point sources None 56. Aberrations Which is least likely to reduce spherical aberration? Use of stops Pantoscopic tilt Aplanatic surfaces Use of a doublet None 57. Aberrations Which of the following adaptations of the eye does not reduce spherical aberration at the retina? Iris position Variable refractive index within lens Vitreous at the posterior lens surface acting as a doublet lens Graduated corneal curvature None 58. Aberrations Which of the following lens types is most likely to cause chromatic aberration? Convex lens with high refractive index Single-element lenses made of low-dispersion glass Bifocal lenses with spherical curvature Lenses with a large aperture and a wide field of view None 59. Aberrations What is the typical effect of spherical aberration in optical lenses? The lens magnifies objects excessively at the center Light rays passing through the optical center are deflected outward Light rays from the center and edges of the lens focus at different points Color fringing occurs around the edges of the image None 60. Visual Function Which of the following is least likely a test of stereoacuity Titmus TNO Pelli-Robson Frisby None 61. Visual Function Which of the following is true about LogMar? The letter spacing is equal to one letter width A LogMAR of +1 is equal to Snellen score of 6/6 A logMAR of 0 is equal to a Snellen score of 6/60 The number of letters increases as you move down the chart None 62. Visual Function Which of the following charts can be used to assess visual acuity in a child less than 1 years old? Keeler cards Sheridan Gardner Kay pictures LogMAR None 63. Visual Function Which of the following is false about LogMAR? he row spacing is equal to the height of a letter from the row below There are five letters on each line Each letter can be assigned a score of 0.01 The letter size increases in 0..1 LogMAR steps None 64. Visual Function What is the visual acuity of a newborn? 6/24 6/200-6/60 6/60 6/18-6/6 None 65. Visual Function What visual angle is subtentendedu by a letter on the 6/6 line of a snellen chart at 6cm? 5 minutes of arc 1 minute of arc 1 second of arc 5 seconds of arc None 66. Visual Function Colour vision is tested using? TNO N-type Cardiff Ishihara None 67. Visual Function Which of the following is used to tests the visual acuity of an 18-month-old child? LogMAR Sheridan-Gardiner Cardiff cards Kay pictures None 68. Visual Function Which of the following is least likely regarding functional vision loss? Optokinetic nystagmus is absent Tunnel vision is seen Presentation is with decreased visual acuity and is more common in females Normal pupil with no RAPD None 69. Visual Function Which of the following is least likely a test of stereo acuity? worth 4-dot Titmus Frisby Cardiff cards None 70. Visual Function Which of the following tests sensory function? Prisms Titmus Bagolini glasses TNO None 71. Visual Function Which of the following tests does not asses colour vision? Pelli-Robson Hardy-Rand-Rittler Farnsworth-Munsell Ishihara None 72. Visual Function A snellen visual acuity of 20/20 is equivalent to which of the following logMAR values? 0.02 0.00 10.00 1.00 None 73. Prisms Which of the the following is least likely regarding the visual image formed by a prism? Diminished Displaced towards the apex Erect Virtual None 74. Prisms A prism deviates light by 5 cm at a distance of 1 meter. What is its prismatic power? 50 prism diopters 5 prism diopters 0.5 prism diopters 10 prism diopters None 75. Prisms Which of the following is least likely to use prisms in spectacle correction? Correction of horizontal diplopia Treatment of presbyopia Treatment of 6th nerve palsy Correction of vertical diplopia None 76. Prisms In vision therapy, prisms are most commonly used to treat which of the following conditions? Strabismus Hyperopia Astigmatism None 77. Prisms Which is most likely about the image formed by a prism? It is virtual and displaced toward the apex It is virtual and displaced towards the base It is real and displaced towards the base It is real and displaced towards the apex None 78. Prisms Which of the following least likely determines the angle of deviation of a ray of light when refracted by a prism? Refractive index of the material of which the prism is made Refracting angle of the prism Wavelength of light of the incident ray Angle of incidence of the ray None 79. Prisms One prism diopter corresponds to a deviation of how many centimeters at a distance of one meter? 5 cm 0.5 cm 1 cm 2 cm None 80. Prisms In the treatment of binocular vision disorders, what effect does using prisms in spectacles typically have on the image? It reduces the field of vision It enlarges the image significantly It shifts the image to aid fusion It causes the image to appear doubled None 81. Prisms Which of the following prisms causes 180 degrees deviation with no left-to-right transposition? Fresnel prism Wollaston prism Dove prism Porro prism None 82. Prisms Which prism causes inversion of the image without deviation or lateral transposition? Porro prism Dove prism Wollaston prism Fresnel prism None 83. Prisms Which of the following statements regarding the Prentice position is least likely? Glass prisms are traditionally held in the prentice position The angle of incidence equals the angle of emergence The incident ray is normal to one surface of the prism The deviation of light is greater in the Prentice position than in the position of minimum deviation None 84. Refraction by the Eye What is the average dioptric power of an aphakic eye? 19 22 58 43 None 85. Refraction by the Eye When does the eye reach its maximum axial length? Does not stop growing 1-3 years old 3-7 years old 13-18 years old None 86. Refraction by the Eye Which most likely describes the far point of the non-accommodated -4.00D myopic eye? The far point is 20cm anterior to the eye The far point and fovea are conjugate points, , The far point is 25cm posterior to the eye The far point is nearer to the eye than is the point of focus of the fully accommodated eye. None 87. Refraction by the Eye What is the size of the adult eye? 34 mm 24 mm 28 mm 17 mm None 88. Refraction by the Eye What is the refractive index of the cornea? 1.33 1.52 1.37 1.40 None 89. Refraction by the Eye What is the radius of curvature (in mm) of the anterior surface of the cornea? 6.8 mm 5.7 mm 7.7 mm 7.0 mm None 90. Refraction by the Eye What is the total approximate refractive power of the human eye? 30D 43D 20D 60D None 91. Refraction by the Eye What is the primary cause of myopia? Corneal irregularity Reduced corneal curvature Excessive axial length Weak accommodation None 92. Refraction by the Eye What is the average axial length of an emmetropic human eye? 20 mm 26 mm 24 mm 22 mm None 93. Refraction by the Eye Which of the following best describes emmetropia? Light focuses in front of the retina without accommodation Light is scattered throughout the eye without a focal point Light focuses exactly on the retina without accommodation Light focuses behind the retina without accommodation None 94. Refraction by the Eye What happens to the eyes during the accommodative reflex? Convergence, miosis, and increased lens curvature Convergence, mydriasis, and lens flattening Divergence, miosis, and lens flattening Divergence, mydriasis, and increased lens curvature None 95. Refraction by the Eye Approximately how much of the eye's total refractive power comes from the cornea? 25% 60D 10% 43D None 96. Refraction by the Eye Which of the following is NOT part of the near triad response? Mydriasis Miosis Convergence Accommodation None 97. Refraction by the Eye A patient with an axial length of 26.5 mm is likely to have: Myopia Presbyopia Hyperopia Emmetropia None 98. Refraction by the Eye Which statement about the optical power of an infant’s eye is true? It is hyperopic due to a short axial length It has a lower refractive power than an adult’s eye It always has a myopic refractive error It has fully developed accommodation at birth None 99. Refraction by the Eye Which lens type is best suited for patients with high myopia (-10.00D and above)? Plus lenses Standard plastic lenses Bifocal lenses Aspheric high-index lenses None 100. Refraction by the Eye Which of the following is true about hyperopia (farsightedness)? The patient may accommodate to compensate for mild hyperopia Light focuses in front of the retina It requires concave lenses for correction It is associated with excessive axial length None 101. Refraction by the Eye Which of the following best describes the process of emmetropization? The gradual loss of accommodation with age The active adjustment of the eye’s axial length and refractive components during development The eye's ability to focus light using accommodation The process of correcting refractive errors using spectacles or contact lenses None 102. Refraction by the Eye Why does the cornea provide more refractive power than the lens? It has a greater curvature. It has a higher refractive index. It is thicker than the lens. It is closer to the retina. None 103. Refraction by the Eye Which previous model is Gullstrand's reduced eye a refinement of? Helmholtz Kepler Schooner Krunenberg None 104. Refraction by the Eye Based on Gullstrand's reduced eye, which of the following points is 7.08mm behind the anterior corneal surface? Nodal point Principle point Second focal point First focal point None 105. Refraction by the Eye In Gullstrand's reduced eye the, how far is the anterior focal point from the anterior cornea? 15.7 cm 17.7 mm 17.7 cm 15.7 mm None 106. Refraction by the Eye The total refractive power of Gullstrand's reduced eye when relaxed is? +58.64 diopter +55.64 diopter +50.64 diopter +60.64 diopter None 107. Refraction by the Eye Which of the following is not proven to slow myopic progression? Outdoor activity Using reading glasses Using atropine None of the above None 108. Refraction by the Eye The most likely effective power of the crystalline lens in situ is? 43 diopters 23 diopters 15 diopter 37 diopters None 109. Refraction by the Eye In a hypermetropic eye, moving a convex lens away from the eye? None of the above The effectivity of the lens is decreased The effectivity of the lens is increased The effectivity of the lens is unchanged None 110. Refraction by the Eye Which is is least likely to be true? The near point at which an object can be clearly seen when maximum accommodation is used The dioptric power of the accommodated eye is called its static refraction The amplitude of accommodation is the dioptric power difference between the eye at rest and when full accommodated The range of accommodation is the distance between the far point and near point None 111. Refraction by the Eye Which ocular structure has the highest refractive power? Vitreous humour Aqueous humour Cornea Lens None 112. Refraction by the Eye Which of the following is true about the lens? The anterior suture gas inverted Y shape The posterior suture has an inverted Y shape The lens becomes more spherical when looking at the distance The posterior capsule thins with age None 113. Refraction by the Eye A high AC/A ratio is most likely associated with? Convergence weakness Convergence excess esotropia Convergence excess exotropia Divergence excess esotropia None 114. Instruments Which optical instrument provides an upright and non-reversed image of the retina? Hruby lens Indirect ophthalmoscope + 20D lens Direct ophthalmoscope Goldman contact lens + slit lamp None 115. Instruments Which one of the following statements about the Geneva lens measure is true? It is calibrated for the refractive index of crown glass It uses three spring-loaded pins to measure the surface curvature of a lens When placed on a convex surface the central pin is extended relative to the peripheral pins It is possible to deduce the total power of a thin lens by measuring both surface powers and calculating the difference between them None 116. Instruments Which optical instrument provides an inverted and reversed image of the retina? Direct ophthalmoscope Indirect ophthalmoscope + 20D lens Goldman contact lens + slit lamp Hruby lens None 117. Instruments Looking through the inferior mirror of a Zeiss 4 mirror goniolensm you see a foreign body at 7 o'clock. Where is this foreign body in your patient? 7 O'Clock 1 O'Clock 11 O'Clock 5 O'Clock None 118. Instruments What factor would reduce your field of view when examining a patient with this instrument: A Moving closer to the patient Hyperopic patient Large pupil size Myopic patient None 119. Instruments Which of the following instruments relies on total internal reflection? Operating microscope Fibre-optic intracular illumination system Gonioscopy lens Direct ophthalmoscope None 120. Instruments Which Volk examination lenses has an image magnification factor of 0.93? 66 dioptre 60 dioptre 90 dioptre 78 dioptre None 121. Instruments Using the following instrument, your image would be: Inverted 9 DD (Disc Diameters) x20 magnified Real None 122. Instruments You examine a patient with the following instrument. Which factor affects your image size: Distance from patient Illumination Patient's refractive state Size of pupil None 123. Instruments Which type of patient cannot be examined using the following instrument: Astigmatic Aphakic Hyperopic Myopic None 124. Instruments Using this instrument how can you enhance your view of the posterior pole in a myopic patient? Ask them to keep their glasses on Use a green filter Stand further away from the patient Use a narrow beam None 125. Instruments Using this instrument how could you enhance your view of a micro-aneurysm? Use a red filter Move away from the patient Remove a myopic patients glasses Use a narrow beam None 126. Instruments The image formed by this instrument is not: Magnified Between the patient and the condensing lens Inverted Real None 127. Instruments What is the field of view achieved with this instrument? 10 degrees 25 degrees 50 degrees 60 degrees None 128. Instruments Your field of illumination is restricted by what when using this instrument? Hyperopic observer Hyperopic patient A small pupil Using a condensing None 129. Instruments Which of the following is true regarding indirect ophthalmoscopy? The image is virtual The image is erect The field of illumination is largest in myopia A +20D concave lens is required None 130. Instruments Your field of view is restricted by what when using this instrument? Small observer's pupil size Small patient's pupil size large patient's pupil size Large observer's pupil size None 131. Instruments You move the condensing lens away from a patient whilst using this instrument. You notice that this causes the image size to increases. This means the patient is: Myopic Hyperopic Emmetropic Moving their head None 132. Instruments You move the condensing lens away from a patient whilst using this instrument. You notice that the image size gets smaller. This means the patient is: Myopic Emmetropic Hyperopic Poorly dilated None 133. Instruments Which one of the following statements about the Hruby lens is incorrect? It has a power of -58.6 dioptres The retinal image formed lies within the eye of the patient It is used with its concave surface towards the observer The retinal image formed is virtual, erect and diminished None 134. Instruments which of the following indirect ophthalmoscopy lens gives the sides field of view? 15, 20, 28 , 30 d 20 D 15 D 28 D 30d None 135. Instruments Which of the following phenomenon is used in optical fibre? Total Internal Reflection Scattering Refraction Diffraction None 136. Imaging In fluorescein fungus imaging which colour is the excitation filter? Yellow Green Blue Red None 137. Imaging Which of the following properties of light is used by the scanning laser polarimeter to measure nerve fibre layer thickness? Power level Focal spot size Pulse duration Polarization None 138. Imaging A patient purchases a pair of yellow sunglasses. Which colour will be hardest to see? Yellow Blue Red Green None 139. Imaging Which of the following components is part of an optical coherence tomography (OCT) system? Split prism Beam splitter Laser light source Double pinhole None 140. Imaging In fluorescein fungus imaging which colour is the barrier filter? Yellow Red Green Blue None 141. Imaging What is the optical principle behind fundus autofluorescence imaging in retinal disease diagnosis? Fluorescence emission from lipofuscin in the retinal pigment epithelium Light scattering from retinal nerve fiber layers Reflection of blue light from the inner retina Absorption of infrared light to highlight choroidal structures None 142. Imaging Which type of light is used in Optical Coherence Tomography (OCT)? Microwave Infrared Ultraviolet X-rays None 143. Imaging Optical Coherence Tomography (OCT) primarily utilizes which principle to obtain high-resolution images of the retina? Diffraction Interference Refraction Fluorescence None 144. Imaging Which of the following best describes fluorescence in ophthalmic imaging? Scattering of light in all directions Complete absorption of light without re-emission Light absorption at one wavelength and emission at a longer wavelength Reflection of light at the same wavelength None 145. Lasers Which of the following light wavelengths can cause photokeratitis? Ultraviolet, Visible light X rays Infrared None 146. Lasers Which of the following is absorbed by haemoglobin and melanin only? Argon blue-green Diode laser PRP Frequency-doubled ND:YAG None 147. Lasers Ophthalmic lasers are under which laser safety class? 3b-4 3a-3b 2 1-2 None 148. Lasers which laser causes it principle effect through photo disruption? Cyclodiode laser Eximer laser Argon laser Nd-YAG laser None 149. Lasers Which laser causes it principle effect through photoablation? Cyclodiode laser Nd-YAG laser Eximer laser Argon laser None 150. Lasers Which of the following characteristics is a property of all ophthalmic lasers? Continuous wave operation A plasma active medium High efficiency Stimulated emission None 151. Lasers Which ophthalmic laser primarily causes its principal effect through photocoagulation? Eximer laser Argon laser Nd-YAG laser Femtosecond laser None 152. Lasers The ability of light wave from a laser to form interference fringes with another wave from the same beam, separated in time, is a measure of its? Spatial coherence Intensity Directionality Temporal coherence None 153. Lasers What is the primary mechanism of the femtosecond laser in cataract surgery? Photoablation Thermal coagulation Photodisruption Photocoagulation None 154. Lasers Which laser emits light at a wavelength of 1064 nm? Nd:YAG laser Diode laser Argon laser Excimer laser None 155. Lasers Which laser is commonly used for selective laser trabeculoplasty (SLT) in open-angle glaucoma? Excimer laser Diode laser Argon laser Nd:YAG laser None 156. Lasers Which laser is primarily used for panretinal photocoagulation (PRP) in diabetic retinopathy? Argon laser Nd:YAG laser Femtosecond laser Excimer laser None 157. Lasers During retinal photocoagulation, which mechanism primarily leads to therapeutic tissue effects? Photoablation Photochemical reaction Photothermal reaction Photodisruption None 158. Lasers Which optical principle is primarily responsible for the effect of laser photocoagulation in retinal surgery? Reflection of laser light causing retinal coagulation Dispersion of light within the vitreous to induce therapeutic heating Absorption of laser energy leading to a photothermal effect Refractive focusing of the laser to create a photomechanical disruption None 159. Cataract Surgery How do accommodating IOLs attempt to restore dynamic near vision? Utilize a pinhole effect to improve near vision Split light into multiple focal points for simultaneous viewing Change curvature dynamically to alter refractive power Shift anteriorly and posteriorly in response to ciliary muscle contraction None 160. Cataract Surgery Which of the following statements correctly describes the relationship between IOL power, axial length and corneal power? The IOL power should increase as the power of the cornea increases and axial length decreases The IOL power should increase as the power of the cornea increases and axial length increases The IOL power should ncrease as the power of the cornea decreases and axial length increases The IOL power should increase as the power of the cornea decreases and axial length decreases None 161. Cataract Surgery Why is no anterior chamber depth (ACD) measurement used in the SRK equation? Postoperative ACD is not necessarily the same as preoperative ACD The SRK was designed to eliminate the need for ACD Modern IOLs are all designed to have the same AC Regression analysis did not show increased accuracy when ACD was included in the SRK formula None 162. Cataract Surgery Which laser is commonly used for posterior capsulotomy after cataract surgery? Excimer laser Femtosecond laser Argon laser Nd:YAG laser None 163. Cataract Surgery Which parameter is least likely to be needed to calculate IOL power before cataract surgery? Central corneal thickness Amount of LASIK treatment Postoperative topography measurements Preoperative refraction None 164. Cataract Surgery Which value is not required in the SRK formula for intraocular lens calculation? Anterior chamber depth Axial length A-constant for the desired IOL Average keratometry reading None 165. Cataract Surgery In a patient with LASIK, which change introduces the most error in the IOL calculations? Anterior chamber depth Axial length Corneal curvature measurements High-order aberrations None 166. Cataract Surgery Which optical phenomenon is most commonly affected by the presence of a cataract? Enhanced night vision due to lens opacification Reduction in axial length, leading to myopic shift Increased light scatter and decreased contrast sensitivity Improved near vision due to reduced corneal astigmatism None 167. Cataract Surgery What optical property of ultrasound waves is essential for phacoemulsification? Refraction of light waves within the lens nucleus enhances fragmentation Chromatic dispersion separates nuclear layers for better emulsification Infrared absorption creates controlled thermal energy to emulsify the lens High-frequency sound waves induce cavitation and lens fragmentation None 168. Cataract Surgery Which optical change is commonly observed after cataract removal? Myopic shift due to corneal steepening Reduced intraocular light scatter and improved night vision Hyperopic shift due to loss of the crystalline lens power Increased astigmatism from irregular corneal wound healing None 169. Cataract Surgery How do multifocal IOLs provide both near and distance vision correction? They induce higher-order aberrations that compensate for presbyopia They dynamically change curvature based on pupil size They use diffractive optics to split incoming light into multiple focal points They selectively absorb short wavelengths to enhance near focus None 170. Cataract Surgery What optical principle allows monovision cataract surgery to provide both near and distance vision? Increasing corneal curvature in one eye to mimic accommodation Adjusting pupil dynamics to selectively refract light Creating anisometropia by implanting different-powered IOLs in each eye Utilizing polarized light filters within IOLs to enhance focus None 171. Cataract Surgery Why do patients with large pupils often struggle with multifocal IOLs? Enhanced near vision at the expense of distance vision Reduced contrast sensitivity due to corneal light scatter Increased exposure to out-of-focus light rays, causing glare and halos Loss of peripheral vision from excessive pupil dilation None 172. Cataract Surgery What is the most critical factor when implanting a toric IOL for astigmatism correction? Ensuring a higher-powered spherical IOL to compensate for residual cylinder Selecting an IOL with a lower refractive index to minimize distortion Precise alignment of the IOL axis to match the patient's astigmatic axis Increasing corneal hydration to reduce astigmatic impact None 173. Cataract Surgery How does small incision cataract surgery (SICS) impact postoperative corneal astigmatism? Induces myopic shift due to decreased corneal thickness Shifts the astigmatic axis to a more oblique orientation Reduces corneal astigmatism by minimizing incision-induced changes Increases irregular astigmatism due to unpredictable corneal wound healing None 174. Cataract Surgery Why are some intraocular lenses designed to filter blue light? To decrease pupil constriction and increase retinal illumination To reduce phototoxic damage to the retina and improve contrast sensitivity To improve dark adaptation by blocking peripheral scatter To enhance near vision by selectively focusing shorter wavelengths None 175. Cataract Surgery How do Extended Depth of Focus (EDOF) intraocular lenses achieve a continuous range of vision? Use of chromatic aberration correction to extend focal points Pinhole optics to minimize out-of-focus blur Increased asphericity to induce controlled spherical aberrations Elimination of multiple focal points to create a single elongated focus None 176. Cataract Surgery Why might a surgeon implant a secondary (piggyback) IOL in a pseudophakic patient? To improve depth perception in monovision patients To reduce spherical aberrations caused by the first IOL To compensate for posterior capsule opacification To correct significant residual refractive error None 177. Cataract Surgery Which optical phenomenon is most likely to affect visual quality in patients with small pupils after multifocal IOL implantation? Widening of peripheral field with loss of central clarity Reduced effect of multifocal optics leading to poor near vision Increased chromatic aberration due to pupil-dependent refraction Increased depth of focus but reduced contrast sensitivity None 178. Cataract Surgery Why are negative-power IOLs sometimes required for extremely high myopia in cataract surgery? The natural crystalline lens has strong positive power, and its removal necessitates a negative correction A posteriorly placed IOL requires negative power for proper light convergence Negative lenses compensate for elongated axial length by neutralizing corneal power Negative lenses enhance retinal image magnification in myopic patients None 179. Cataract Surgery What optical aberration is most commonly induced when an IOL is significantly decentered postoperatively? Coma Spherical aberration Chromatic aberration Barrel distortion None 180. Cataract Surgery How does reverse optic capture influence refractive outcomes in IOL implantation? Pushes the IOL posteriorly to induce a hyperopic shift Increases posterior capsule opacification by trapping lens fibers Minimizes glare and halos by reducing light scatter at the IOL edge Reduces higher-order aberrations by stabilizing the IOL None 181. Cataract Surgery What optical principle contributes to positive dysphotopsia in some IOL patients? Excessive chromatic dispersion from multifocal optics Pupil-dependent refraction misalignment Internal reflection of light at the IOL edge Light scattering due to incomplete posterior capsule opacification None 182. Refractive Surgery Which of the following is not a complication of refractive eye surgery? PCO Dry eyes DLK Glare None 183. Refractive Surgery How long should soft contact lenses be withheld for before undergoing laser eye surgery? 7-14 days 14-21 days 21-28 days 28-35 days None 184. Refractive Surgery A corneal flap is created, the storm is then ablated, and the flap is replaced. what is this a description of? YAG laser capsulotomy PRK LASEK LASIK None 185. Refractive Surgery Which of the following is not an intervention for myopic correction? Central corneal ablation with LASIK Peripheral corneal ablation with LASIK Negative diopter lens Central corneal ablation with LASEK None 186. Refractive Surgery Which of the following is a key difference between PRK and LASIK? LASIK has a slower visual recovery than PRK PRK does not require a corneal flap PRK removes less corneal tissue than LASIK LASIK has a higher risk of corneal haze None 187. Refractive Surgery Which of the following is a contraindication for LASIK surgery? Keratoconus History of dry eyes Presbyopia A) Mild myopia (-2.00D) None 188. Refractive Surgery Why might a phakic IOL (ICL) be preferred over LASIK in some patients? Phakic IOLs preserve the cornea LASIK is more effective Phakic IOLs are only used in presbyopia LASIK is the only option for high myopia None 189. Refractive Surgery What is the primary advantage of SMILE (Small Incision Lenticule Extraction) over LASIK? Faster recovery Better correction of hyperopia Less risk of dry eye No need for a femtosecond laser None 190. Refractive Surgery Which instrument is the most accurate for measuring anterior chamber depth? Slit lamp with Van Herick technique Direct ophthalmoscope Pentacam (Scheimpflug imaging) Indirect ophthalmoscope None 191. Refractive Surgery Why are IOL power calculations more challenging in post-LASIK patients? The axial length is affected by previous refractive surgery The effective lens position is unpredictable due to changes in corneal biomechanics The residual epithelial thickness alters the refractive index of the cornea Corneal power is inaccurately estimated due to altered curvature None 192. Retinal Surgery Which optical phenomenon contributes to improved visualization of the retina during surgery under a microscope? Reduction of spherical aberration using coaxial illumination Enhancement of retinal contrast via polarized light filtering Total internal reflection at the vitreous-retinal interface Light scattering due to small pupil size None 193. Retinal Surgery Silicone oil in aphakic eye leads to? Hyperopic shift Myopic shift No change Blindess None 194. Retinal Surgery Why are wide-angle viewing systems preferred in modern retinal surgery? They increase image brightness by eliminating reflections from the corneal surface They reduce chromatic aberration and enhance color contrast in retinal structures They magnify the central retina, allowing for more detailed surgical precision They provide a panoramic view of the peripheral retina without requiring frequent lens adjustments None 195. Retinal Surgery Which optical property makes perfluorocarbon liquids (PFCL) useful in vitreoretinal surgery? Selective absorption of short-wavelength light, reducing phototoxicity High viscosity, preventing intraoperative turbulence Low refractive index, improving light transmission through the vitreous High specific gravity allowing mechanical flattening of the retina None 196. Retinal Surgery Which refractive change is commonly observed following pars plana vitrectomy with gas tamponade? Myopic shift Hyperopic shift Astigmatic shift No significant refractive change None 197. Retinal Surgery Which optical aberration is most commonly encountered when performing wide-field retinal imaging? Coma from off-axis light sources Distortion due to peripheral magnification differences Spherical aberration from excessive lens curvature Chromatic aberration from lens dispersion None 198. Retinal Surgery What optical principle makes endoillumination essential for vitreoretinal surgery? Total internal reflection of fiber-optic light enhances contrast High refractive index of fiber optics ensures focused light delivery Polarization reduces glare and enhances macular detail Scattering within the vitreous helps illuminate deep retinal layers None 199. Prescriptions Which bifocal segment design provides the widest near reading area? Flat-top bifocal Round-segment bifocal Progressive lens Executive bifocal None 200. Prescriptions Which of the following is an advantage of soft contact lenses over RGP lenses? Lower risk of corneal infections Higher oxygen permeability More effective in correcting keratoconus Better initial comfort None 201. Prescriptions An adult has diplopia and a left hypertrophic of 6Δ. which combination of prisms in his glasses will most likely align the two images for him? 3Δ base down (OD), 3Δ base up (OS) 6Δ base down (OD), nothing (OS) 3Δ base up(OD), 3Δ base down (OS) 4Δ base down (OD), 2Δ base down (OS) None 202. Prescriptions Which test is commonly used to measure the amplitude of accommodation? Bagolini striated lenses Maddox rod test Push-up test Worth 4-dot test None 203. Prescriptions What type of image distortion is most common with high-plus (hyperopic) lenses? Barrel distortion Coma Chromatic aberration Pincushion distortion None 204. Prescriptions What strength of lens is needed so that a patient with 20/160 visual acuity can read newsprint without accommodation? +5.00 D +10.00 D +8.00 D +12.50 D None 205. Prescriptions Which aberration is reduced by using aspheric lenses? Chromatic aberration Spherical aberration Coma Distortion None 206. Prescriptions A Maddox rod is place in front of a patient's right eye with its axis vertical. She is asked to look at a white spot and sees a horizontal red line with the light above it. What does that indicate? Exophoria Right hypophoria Esophoria Right hyperphoria None 207. Prescriptions You use the duochrome test to refine the refraction of a patient. The patient says the red letter are much clearer than the green. The patient is: Overplussed Astigmatic Anisometropic Overminused None 208. Prescriptions Which optical issue do progressive lenses correct that bifocals do not? High astigmatism Near vision Intermediate vision Distance vision None 209. Prescriptions What is the primary purpose of the Jackson Cross Cylinder (JCC) test? To determine near addition power To refine the axis and power of astigmatism To measure spherical refractive error To assess accommodation ability None 210. Prescriptions What type of patient benefits the most from myodisc lenses? High myopia Presbyopia High hyperopia Astigmatism None 211. Prescriptions What is the primary purpose of an anti-reflective coating on eyeglass lenses? To prevent all light from entering the eye To reduce glare and ghost images To create a mirror effect on the lens surface To increase light reflection for better contrast None 212. Prescriptions The base curve of a contact lens is primarily chosen based on which measurement? Anterior chamber depth Pupil size Lens diameter Central keratometry readings None 213. Prescriptions What is a key advantage of Fresnel prisms in ophthalmic use? They provide higher magnification. They do not require refraction correction. They are lightweight and flexible. They reduce chromatic aberration. None 214. Prescriptions Which function of the tear film is most critical for successful contact lens wear? Maintaining corneal hydration Creating a smooth optical surface Providing nutrients to the cornea Removing debris from the eye None 215. Prescriptions What is unique about gradient index (GRIN) lenses compared to standard lenses? They can only be used in microscopes. They have a uniform refractive index throughout the material. They work only for concave lenses. They have a continuously varying refractive index. None 216. Prescriptions In clinical practice, a Maddox rod is used to assess which of the following? Ocular alignment Intraocular pressure Color vision Visual acuity None 217. Prescriptions How does increasing the base curve radius affect a contact lens fit? It has no effect on fit. It loosens the lens fit. It tightens the lens fit. It increases the lens power. None 218. Prescriptions What is the primary effect of high-minus spectacle lenses on retinal image size? It increases magnification. It induces a prismatic shift. It has no effect on image size. It reduces image size. None 219. Prescriptions Which type of spherical lens is used to correct myopia? Concave (diverging) lens Plano-convex lens Convex (converging) lens Cylindrical lens None 220. Prescriptions Which optical phenomenon may cause double vision when a prism is incorrectly placed in spectacles? Chromatic aberration Ghosting Monocular diplopia Image displacement None 221. Prescriptions How does a pinhole improve vision in a hyperopic patient? It increases accommodation. It magnifies the image. It increases depth of focus by reducing peripheral blur. It increases the corneal curvature. None 222. Prescriptions What is the primary purpose of a retinoscope in clinical practice? To measure refractive error objectively To visualize the anterior chamber To examine the retina To assess intraocular pressure None 223. Prescriptions Which type of contact lens is most commonly used to correct aphakia? High-plus silicone hydrogel soft lens Scleral lens Rigid gas-permeable (RGP) corneal lens Hybrid lens with aspheric optics None 224. Prescriptions Which of the following is a correct transcription of a 0.50 Jackson's Cross cylinder? +0.50 DS/ -0.50 DC +0.25 DS/ -0.50 DC +0.50 DS/ -0.25 DC +0.25 DS/ -0.25 DC None 225. Prescriptions Regarding the Jackson's cross cylinder? The cylinder in the cross cylinder has twice the power of the sphere It is equivalent to two superimposed cylindrical lenses with axes at 45 degrees to each other The cross cylinder's handle is held in line with the axis of the trial cylinder The handle is traditionally in line with the axis of the negative cylinder None 226. Prescriptions Which is least likely in spectacle correction for aphakia? Pin fusion distortion Ring scotoma Image magnification Barrel distortion None 227. Prescriptions Which of the following regarding contact lenses is used in patients with dry eyes? Soft lenses Rigid lenses Monthly lenses Silicone hydrogel None 228. Prescriptions A patient is fitted with a rigid gas permeable contact lens. The average K reading is 7.67mm, and the base curve of the lens in 7.5 mm. What is the shape of the resultant tear lens? No tear lens will be formed Concave Plano Convex None 229. Prescriptions In a myopic patient, which of the following is increased with contact lens wear compared to glasses? Optical aberrations Aniseikonia Image magnification Image distortion None 230. Prescriptions Which of the following statement is correct regarding the segment choice when prescribing bifocals for a patient with hyperopia? The use of a round-top segment reduces the prismatic displacement effect and increases image jump A flat-top segment is preferred because of its thin upper edge which causes less prismatic effect The practitioner should leave the choice of the segment type to the optician, A round-top segment is preferred because it lessens image jump None 231. Prescriptions A patient with a red Maddox rod with the cylinders orientated horizontally placed over her left eye. What does she see when she views a distant white fixation light? Red light, vertical red line Red light, horizontal red line White light, horizontal red line White light, vertical red line None 232. Astigmatism Which of the following is an advantage of rigid gas permeable (RGP) contact lenses over soft lenses? Does not require lens care Greater initial comfort Reduced risk of corneal hypoxia Higher oxygen permeability None 233. Astigmatism Which type of lens is used to correct astigmatism? Plano-convex lens Prism lens Cylindrical lens Spherical lens None 234. Astigmatism In against-the-rule (ATR) astigmatism, the steepest meridian is located at approximately: 135° 180° 45° 90° None 235. Astigmatism In simple myopic astigmatism, how does light focus? Both focal points are behind the retina. One focal point is on the retina, and the other is behind the retina. One focal point is on the retina, and the other is in front of the retina. Both focal points are in front of the retina. None 236. Astigmatism What type of astigmatism is more commonly seen in older adults? Oblique astigmatism Irregular astigmatism With-the-rule astigmatism Against-the-rule astigmatism None 237. Astigmatism In a cylindrical lens, where does the full power of the lens act? Perpendicular to the axis Along the axis Evenly across the entire lens At 45° to the axis None 238. Astigmatism In a patient with regular astigmatism, how are the principal meridians positioned? Perpendicular to each other At 30-degree intervals Randomly aligned Parallel to each other None 239. Astigmatism Where does a cylindrical lens exert its refractive power? Equally across the entire lens Perpendicular to the axis of the lens Along the axis of the lens At the center of the lens None 240. Astigmatism A patient’s vision improves with a stenopaic slit placed at 90°. What type of refractive error does this suggest? Simple hyperopia Simple myopia Against-the-rule astigmatism With-the-rule astigmatism None 241. Astigmatism Which of the following is used to manage keratoconus? LASEK Rigid contact Lenses Toric lenses LASIK None 242. Astigmatism In simple hypermetropic astigmatism? Both focal lines are in front of the retina One focal line is on the retina whilst the other is behind it Both focal lines are behind the retina The focal lines are straddling the retina None 243. Astigmatism Which of the following prescriptions is an example of 'with the rule' astigmatism? +3.50 DS/ -0.75 DC axis 90 -5.25 DS/ +2.50 DC axis 180 +3.00 DS/ +2.25 DC axis 85 -1.50 DS/ -1.00 DC axis 45 None 244. Astigmatism Keratoconus most likely causes? Refractive myopia Axial hypermetropia Axial myopia Refractive hypermetropia None 245. Astigmatism If rays of light from all meridians come into focus behind the retina, this is called? Compound myopic astigmatism Simple hypermetropic astigmatism Simple myopic astigmatism Compound hypermetropic astigmatism None 246. Low Vision Aids Which low vision aid can help a patient with Age Related Macular Degeneration watch TV? Galilean telescope Magnifying glass loop magnifiers Hubble telescope None 247. Low Vision Aids What is the primary purpose of low vision aids in the management of patients with visual impairment? To restore normal vision To magnify images for clearer vision To eliminate the need for corrective lenses To treat underlying eye diseases None 248. Low Vision Aids Which of the following low vision aids is best suited for improving distance vision in individuals with low vision? Reading glasses Telescopic lenses Bifocal lenses Magnification spectacles None 249. Low Vision Aids Which of the following low vision aids is most commonly used for close-up tasks such as reading? Fresnel prisms Visual field expanders Telescopic lenses High-powered magnifying glasses None 250. Low Vision Aids Which of the following statements about the Galilean telescope is least likely? The objective and eye piece lenses are separated by the difference between their focal lengths It is composed of two convex lenses The image is typically dimmer than seen with the unaided eye It has an extremely narrow field of view None 251. Low Vision Aids What role do prisms play in binoculars? They increase the brightness of the image. They invert and erect the image. They allow light to be focused at a single point. They reduce chromatic aberration. None 252. Low Vision Aids Which of the following best describes the image produced by a Galilean telescope? Virtual, erect, magnified, at the sum of the focal lengths of the objective and eyepiece lens Virtual, inverted, magnified, at the sum of the focal lengths of the object and eyepiece lens Virtual, erect, magnified at infinity Virtual, inverted, magnified, at infinity None 253. Low Vision Aids Which optical application commonly uses a plano-convex lens? Camera telephoto lens Myopia correction Magnifying glass Optical fiber focusing None 254. Clinical Which of the following is not associated with myopia? Congenital glaucoma ROP RRD Uveal effusion syndrome None 255. Clinical Which of the following is used to distinguish between open and closed angle glaucoma? Fundoscopy Gonioscopy Perimetry Tonometry None 256. Clinical What investigation is used to measure corneal curvature? Perimetry Keratometry Tonometry Pachymetry None 257. Clinical A patient with presbyopia says he can now see without his reading glasses, Which cataract does the patient have? Nuclear sclerotic Anterior subcapsular Posterior subcapsular Cortical None 258. Clinical Which of the following structures is affected leading to presbyopia? Zonules Cornea Lens Iris None 259. Clinical Which of the following factors increases the risk of infection in a patient using extended wear contact lenses? Normal eyelid function Intact corneal epithelium Switching to daily -wear contacts Exposure to smoke None 260. Clinical Regarding the prevalence of myopia (of at least -0.5 dioptres): Myopis tends to decrease with nuclear sclerosis of the lens It is lower in adults than in young children It is high in white Europeans compared to other ethnicities Time spent outdoors as a child is a protective factor agains myopia None 261. Clinical A child has a cycloplegia refraction 0D +6.00D, OS +2.00. What is the best way to manage the anisometropia? Full correction Paleoptic therapy Occlusion therapy Partial correction None 262. Clinical Which lens can be used to examine the anterior chamber angle? Three mirror lens Hruby lens 90D lens Wide field lens None 263. Clinical Which of the following indirect ophthalmoscopy lenses gives the greater magnification? 20 D 28 D 15 D 30 D None 264. Clinical How does corneal edema primarily affect vision? Increases light scatter Causes hyperopia Enhances contrast sensitivity Induces myopia None 265. Clinical Which of the following is a common optical correction for presbyopia? Cylindrical lenses Plano convex lenses Progressive addition lenses (PALs) Single-vision myopic glasses None 266. Clinical What is the primary cause of presbyopia? Loss of lens elasticity Corneal steepening Increase in axial length Weakening of the extraocular muscles None 267. Clinical Which factor is least likely to influence the onset of presbyopia? Refractive error Gender Geographic location Age None 268. Spherical Lenses How is the image formed by a convex lens of an object located inside the first focal point best described? Erect, virtual, further from lens than object, magnified Erect, real, inside age second focal point, diminished Inverted, real, outside the second focal point, magnified Inverted, virtual, at infinity, diminished None 269. Spherical Lenses What role does a concave lens play in a Keplerian telescope? It magnifies the image without altering the focal length It enhances color contrast by removing chromatic aberration It corrects the inverted image formed by the convex objective lens It increases the field of view while maintaining image size None 270. Spherical Lenses For a convex lens, placing an object outside the first principle focus results in an image that is Magnified, inverted, virtual Erect, real Enlarged, erect, virtual Inverted, real None 271. Spherical Lenses A higher refractive index lens has which of the following advantages? Increased lens thickness Reduced lens thickness Increased chromatic aberration Increased spherical aberrations None 272. Spherical Lenses The image formed by a thin concave lens is? Real, inverted, magnified, outside the second focal point Virtual, inverted, diminished at infinity Virtual, erect, diminished, inside the second focal point Real erect, magnified, further from the lens than the object None 273. Spherical Lenses Tilting a spherical lens can induce which type of optical effect? Reduced power No effect Induced prism Elimination of aberrations None 274. Spherical Lenses What happens when the curvature of a spherical lens increases? The refractive index of the lens material changes The focal length increases, reducing the lens’s optical power The lens starts to behave like a prism instead of a spherical lens The focal length decreases, making the lens more powerful None 275. Spherical Lenses Which factor increases the optical power of a spherical lens, assuming the shape remains the same? Reducing the curvature of the lens surfaces Using a material with a higher refractive index Increasing the focal length of the lens Decreasing the thickness of the lens None 276. Spherical Lenses What type of image is always produced by a concave (diverging) spherical lens? Virtual, inverted, and same size as the object Real, inverted, and magnified Real, upright, and larger than the object Virtual, upright, and smaller than the object None 277. Spherical Lenses Which factor increases the optical power of a spherical lens, assuming the shape remains the same? Using a material with a higher refractive index Decreasing the thickness of the lens Increasing the focal length of the lens Reducing the curvature of the lens surfaces None 278. Spherical Lenses Which statement is true regarding the difference between a biconcave and a plano-concave lens? A plano-concave lens has equal power on both sides A plano-concave lens is used to converge light rays A biconcave lens has two concave surfaces and more negative power A biconcave lens forms only real images None 279. Spherical Lenses What happens to the focal length of a convex lens when it is submerged in water? It remains the same because focal length is a material property It increases because the refractive index contrast between the lens and water is reduced It depends only on the lens curvature, not the surrounding medium It decreases because water enhances light bending None 280. Jokes 😉 Why do people randomly test themselves for color blindness online? Because they saw a meme that convinced them they’ve been colorblind their whole life. Because it’s a convenient way to procrastinate at work. Because they want to prove their friends wrong in an argument about "blue or green?" Because they need to know whether they’d survive as a bomb defuser in an action movie. None 281. Jokes 😉 What’s the real reason optometrists get excited about astigmatism? Because prescribing cylindrical correction makes them feel like wizards. Because saying “with-the-rule astigmatism” makes them feel fancy. Because they secretly enjoy watching patients struggle with JCC testing. Because it’s a good excuse to show off their maths skills. None 282. Jokes 😉 What is the most common reaction after LASIK surgery? “Can I get a refund if I still need glasses?” “So… I paid thousands of dollars and now I have dry eyes forever?” “My vision is so clear, I can now see all my life mistakes.” “Wow, I can see! Time to read the fine print on my medical bills.” None 283. Properties of Light A beam of light passes from air into glass at an angle. What happens to its frequency? It increases. It decreases. It becomes zero. It remains the same. None 284. Properties of Light Which of the following is least likely to happen when constructing a correct ray diagram? At least two rays are required to locate an image. The image forms where the reflected or refracted rays intersect. If the rays appear to diverge, a virtual image is formed. Rays that do not intersect will eventually converge if extended. None 285. Properties of Light Destructive interference is most likely in: Refraction Corneal endothelium Corneal epithelium Antireflective lens coatings None 286. Properties of Light When light moves from air to water and travels towards the normal at the interface, which of the following is more likely to happen? The light will bend away from the normal The light will not bend at all. The light will bend towards the normal. The light will undergo total internal reflection. None 287. Properties of Light Which statement about the speed of light is correct? Light travels at the same speed in all mediums. Light speeds up when entering a denser medium. Light travels fastest in water. Light slows down when entering a denser medium. None 288. Properties of Light Which of the following terms best describes a substance which only allows the transmission of light in an incident plane aligned with its structure, by absorbing other light waves? Scattering Dichroic Mirrored birefringent None 289. Properties of Light Which of the following is most likely the correct rule for drawing a principal ray in a concave mirror ray diagram? A ray passing through the centre of curvature (C) reflects at a random angle. A ray parallel to the principal axis reflects through the center of curvature (C). A ray incident at the mirror surface always travels straight without reflection. A ray passing through the focal point (F) reflects parallel to the principal axis. None 290. Properties of Light Which change is most likely when a ray of light passes into a denser medium? Frequency and plane Velocity only Velocity and frequency Velocity and plane None 291. Properties of Light Which definition most likely describes radiant flux? The amount of light reflected from a surface The intensity if light emitted from a source The amount of light emitted from a source The amount of light falling in a surface None 292. Properties of Light The image of an object formed by reflection at a plane surface is least likely to be? Diminished Erect Virtual Laterally inverted None 293. Properties of Light How is surface illumination related to the distance from the light source? Inversely proportional Directly proportional to the square root Directly proportional Inversely proportional the square root None 294. Properties of Light Regarding optical radiation, which of the following is least likely? Shorter wavelengths undergo increased scatter Light emitted through fluorescence typically has a longer wavelength than the excitation light that trigger it The energy of a photon is directly proportional to its wavelength The wavelength of light decreases as it enters a transparent material from a vacuum None 295. Properties of Light What causes the appearance of a secondary rainbow? Diffraction of light waves A change in the sun’s intensity Multiple internal reflections inside raindrops A different type of water droplet composition None 296. Properties of Light Wavelength is best defined as? One complete oscillation The distance between two symmetrical parts of the wave motion Any portion of the cycle The maximum displacement of an imaginary particle on the wave from the baseline None 297. Properties of Light What type of reflection occurs on a rough surface? Diffuse reflection Polarized reflection Total internal reflection Specular reflection None 298. Properties of Light What does polarized light consist of? Light waves oscillating in multiple planes Light waves oscillating in a single plane Light waves with equal wavelengths Light waves with reduced intensity None 299. Properties of Light Total internal reflection occurs is most likely if the incident ray strikes the interface of media at? The critical angle An angle greater than the critical angle An angle less than the critical angle 90 degrees None 300. Properties of Light The most likely unit of illuminance is? Lux (human per square metre) Lumen Cadelas (lumen per steradian) Watts per steradian None 301. Properties of Light Which catastrophic image is most likely to form an inverted image? Add description here! Posterior lens surface Anterior lens surface Posterior corneal surface Anterior corneal surface None 302. Properties of Light Which type of light wave carries the most energy? Ultraviolet light Blue light Infrared light Red light None 303. Properties of Light Which of the following statements about convave lenses is TRUE? They always produce virtual images They cause light to diverge They converge parallel light rays to a focal point They are used to correct myopia None 304. Properties of Light Which of the following correctly describes light? It is a longitudinal wave. It requires a medium to travel. It travels at the same speed in all materials. It can exhibit both wave and particle properties. None 305. Properties of Light Which of the following factors affects the scattering of light in the eye? Corneal thickness Lens elasticity Wavelength of light Intraocular pressure None 306. Properties of Light What is the main law governing the reflection of light? Fermat’s Principle Snell’s Law Law of Equal Angles Brewster’s Law None 307. Properties of Light What happens to light as it moves from a less dense medium (air) to a denser medium (cornea)? It remains unaltered It slows down and bends toward the normal It bends away from the normal It speeds up None 308. Properties of Light Which of the following pairs is matched correctly? Refractive index-meters per second Wavelength-nanometers Prism diopter-meters per centimetre Dioptre-meter None 309. Properties of Light Which of the following statements about convex lenses is TRUE? They cause light to diverge They always produce virtual images They are used to correct myopia They converge parallel light rays to a focal point None 310. Properties of Light Which optical principle explains the formation of mirages? Reflection Diffraction Refraction Dispersion None 311. Properties of Light Which color of visible light has the shortest wavelength? Green Blue Red Yellow None 312. Properties of Light When the angle of incidence is greater than the critical angle? Total Internal reflection occurs Total external refraction occurs The angle of incidence cannot be greater than the critical angle Reflection mostly occurs with some refraction None Please fill in the comment box below. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time's up
April 15 2025 Histopathology Ryian mohamed 0 1. Cornea Which layer of the cornea contains keratocytes? Epithelium Bowman's layer Stroma Descemet’s membrane Endothelium None 2. Retina The internal limiting membrane of the retina is formed by: Müller cell footplates Astrocytes Photoreceptor nuclei Retinal pigment epithelium Ganglion cells None 3. Retina Drusen are histopathological features seen in: Diabetic retinopathy Retinitis pigmentosa Age-related macular degeneration Uveitis Retinoblastoma None 4. Cornea The primary site of lesion in keratoconus is: Epithelium Bowman's layer Stroma Descemet's membrane Endothelium None 5. Pathology Rosette formations on histopathology are characteristic of: Retinoblastoma Conjunctival lymphoma Orbital cellulitis Choroidal nevus None 6. Cornea Which structure is acellular and acts as the basement membrane for the corneal endothelium? Stroma Bowman's layer Descemet's membrane Bruch’s membrane Internal limiting membrane None 7. Pathology Fuchs endothelial dystrophy primarily affects which corneal layer? Epithelium Stroma Endothelium Bowman's layer Limbus None 8. Pathology Psammoma bodies may be seen in histology of which orbital tumor? Cavernous hemangioma Optic nerve glioma Schwannoma Meningioma Rhabdomyosarcoma None 9. Eyelids Which type of gland is the Meibomian gland classified as? Apocrine Sebaceous Eccrine Endocrine Mucous None 10. Retina Which retinal layer contains the nuclei of photoreceptor cells? Inner nuclear layer Outer nuclear layer Ganglion cell layer Outer plexiform layer Retinal pigment epithelium None Time's up
March 18 2025 Optics Ryian mohamed 0 Welcome to Optics 😉 Name Email 1. Please select your category: Please select your answer Properties of Light Prescriptions Spherical Lenses Aberrations Refractive Surgery Lasers Prisms Calculations Mirrors Retinal Surgery Cataract Surgery Jokes Refraction by the Eye Clinical Imaging Astigmatism Instruments Visual Function Low Vision Aids 2. Calculations What is the optical power (D) of a convex spherical lens with a focal length of 25 cm? +4.00D -2.50D +2.50D -4.00D None 3. Calculations Transpose the -4.00 DS/ -3.00 DC X 45 into positive cylinder notation? −7.00 DS/ +3.00 DCx135 −7.00 DS/ +3.00 DCx45 −5.50 DS/ +3.00 DCx45 −5.50 DS/ +3.00 DCx135 None 4. Calculations A hypermetrope whose glasses contain +5.00 DS lenses wants to wear contact lenses. What is the dioptric power of the contact lens that he would require? (Back vertex distance = 15 mm) - 5.0 dioptres + 5.8 dioptres +4.5 dioptres + 5.4 dioptres None 5. Calculations A crown glass prism in air has an apical angle of 4 degrees. What will the approximate angle of deviation be in the position of minimum deviation? 2 degrees 16 degrees 4 degrees 8 degrees None 6. Calculations A glass prism (refractive index 1.5) of 20 prism diopters deviates an incident of ray of light through? 20 degrees 5 degrees 10 degrees 40 degrees None 7. Calculations The spherical equivalent of a lens with power +3.00DS/-2.00 DC is? -0.50 DS +2.00 DS -1.00 DS +1.00 DS None 8. Calculations Transpose +2.00 DS/ -1.00 DC x 180 to the base curve -2.00 D? +4.00 DS/ (-2.00 DC x 90/-3.00 DC x 180) +4.00 DS/ (-2.00 DC x 90/+1.00 DC x 180) +4.00 DS/ (-3.00 DC x 90/-3.00 DC x 180) +4.00 DS/ (-2.00 DC x 90/-1.00 DC x 180) None 9. Calculations What is the magnification of a loupe of power +16 diopters? x 4 x 64 x 8 x 32 None 10. Calculations An eye has axial length 23.0mm, with average keratometry readings of 42 diopters. Using the SRK formula (constant 118.9), aiming for emmetropia, the calculated power of an intraocular lens implant would be: 24.30 D 23.60 D 23.30 D 24.60 D None 11. Calculations What is the dioptric lens power of simple magnifying glass (loupe) with a magnification of 2.5x? 4 dioptres 10 dioptres 2.5 dioptres 25 dioptres None 12. Calculations What is the accommodative power required for a myope with a -1.5 dioptre prescription to read unaided at 25 cm? 7 dioptre 5.5 dioptre 1 dioptre 2.5 dioptre None 13. Calculations What magnitude of accommodation will be required for a hypermetropic patient within +2 dioptre prescription to read unaided at 20cm? 7 dioptres 5 dioptres 10 dioptres 3 dioptres None 14. Calculations A patient's prescription is +2.00 DS/ -1.00 DC axis 180. What is the topic transposition of this to the base curve -4.00 D? +1.00 DS/ (+1.00 DC x 90/-5.00 DC x 180) +6.00 DS/ (-4.00 DC x 90/-5.00 DC x 180) +1.00 DS/ (-5.00 DC x 180/+1.00 DC x 90) +6.00 DS/ (-4.00 DC x 180/-1.00 DC x 90) None 15. Calculations What is the degree of magnification when viewing the funds of a patient with 10 dioptres of myopia with a direct ophthalmoscope? x 17.5 x 15 x 12.5 x 2.5 None 16. Calculations What is the lens to object working distance of a simple magnifying glass of 2.5 x magnifications? 10 cm 2.5 cm 20 cm 5 cm None 17. Calculations Which of the following transpositions is incorrect? +4.50/ -2.25 x 140 = +2.25/ +2.25 x 50 -3.75/ -1.75 x 80 = -5.50/ +1.75 x 170 +2.00/ -3.25 x 20 = +1.25/ +3.25 x 110 -1.75/ -1.25 x 60 = -3.00/ +1.25 x 150 None 18. Calculations A +4.00D spectacle lens is decentered 5 mm nasally. What type of prism effect is induced? 2Δ Base In 2Δ Base Up 2Δ Base Out No prism is induced None 19. Calculations What is the tube length of an astronomical telescope with a +4.00D objective lens and a +10.00D eyepiece lens 15 cm 30 cm 35 cm 20 cm None 20. Calculations What is the prismatic effect (prism dioptres) of a 4 dioptre lens that has been decanted by 30 mm? 30 12 0.75 120 None 21. Calculations An object is placed 50cm in front of a concave spherical mirror with a radius of curvature of 2.0m. What image is produced? Virtual, enlarged Real, diminished Virtual, diminished Real, enlarged None 22. Calculations What is the Brewster angle when light travels from air to glass (n= 1.50)? 65.7 41.8 56.3 47.6 None 23. Calculations How much does a 15Δ prism bend light, in degrees? 12.4 degrees 7.5 degrees 15 degrees 8.53 degrees None 24. Calculations What is the critical angle for light travelling from glass (n=1.50) to air? 65.7 degrees 47.6 degrees 56.7 degrees 41.8 degrees None 25. Calculations Convert the following spectacle prescription from plus-cylinder to minus-cylinder notation: +2.00 / +1.50 × 90 +0.50 / -1.50 × 180 +3.50 / -1.50 × 180 +2.00 / -1.50 × 180 +3.50 / -1.50 × 90 None 26. Calculations If a cornea has an anterior radius of curvature of 7.7 mm, a posterior radius of curvature of 6.8 mm, and a centre of thickness of 0.5 mm, what will its dioptric power be if it is submerged in water? Assume index of refraction of water =1.333; index of refraction of cornea = 1.376; index of refraction of aqueous = 1.336 -5.89 D -0.30 D +32.00 D +37.60 D None 27. Calculations A cyclopegic refraction is performed for on a non verbal, adult patient at a testing distance of 67 cm. The results for the right eye is as follows: +3D share neutralises the reflex when the streak is horizontal (180 degrees); +4D sphere neutralises the reflex when the streak is vertical ( 90 degrees). What is the refraction of the right eye? +1.50 (sphere) + 1.00 x90 +3.00 (sphere) + 1.00 x90 +1.50 (sphere) - 1.00 x90 +3.00 (sphere) - 1.00 x90 None 28. Calculations During cataract surgery on a patient with an eye of axial length of 23 mm, it becomes necessary to change the IOL type. The A constant for the original IOL is 118.4 and will give a bower of 21.5 dioptres. The A constant for the new IOL is 117.4. What is the power of the new IOL? 21.0 dioptres 22.5 dioptres 20.5 dioptres 22.0 dioptres None 29. Calculations An object is placed 50cm in front of a concave spherical mirror with a radius of curvature of 2.0m. What is the transverse magnification of the image? x2 x1 x3 x4 None 30. Calculations At 20 feet, the smallest letters that a child;d can read is the 20/60 line. You have the child walk towards the eye chart. How far does she walk before she can see the 20/20 line? 15 feet 13 feet 7 feet 5 feet None 31. Calculations What is the maximum amplitude of accommodation of an emmetropic patient with a near point of 20 cm? 10 dioptres 2 dioptres 5 dioptres 8 dioptres None 32. Calculations Using this instrument with a +13D lens where is the image 0.08 cm behind the lens 0.08 cm in front of the lens 8 cm in front of the lens 8 cm behind the lens None 33. Calculations An object is placed 50cm in front of a concave spherical mirror with a radius of curvature of 2.0m. What is the power of the mirror? +1.00 -2.00 -1.00 +2.00 None 34. Calculations If a 10 dioptre concave lens is decentered by 2cm temporally, this will result in a: 5 prism dioptre base-in prism 20 prism dioptre base-out prism 20 prism dioptre base-in prism 5 prism dioptre base-out prism None 35. Calculations What is the spherical equivalent of -3.50/+1.50 axis 70? -5.00 DS -2.00/-1.50 axis 110 -2.75 DS -2.00 DS None 36. Calculations During cataract surgery a complication occurs and the decision is made to place the intraocular lens (IOL) in sulcus. A 23.5 diopter IOOL has been planned for placement in the capsular bag. Which of the following lens powers is most appropriate for placement in the sulcus? 24.5 dioptre 21.50 dioptre 22.50 dioptre 25.5 dioptre None 37. Mirrors Which type of mirror is commonly used in car rearview mirrors? Plane mirror Parabolic mirror Convex mirror Concave mirror None 38. Mirrors What optical principle allows a kaleidoscope to form symmetrical patterns? Chromatic aberration Diffraction Total internal reflection Dispersion None 39. Mirrors The object lies outside the centre of curvature of a concave mirror. How is the image formed by the mirror best best described? Real inverted diminished Real inverted enlarged Virtual erect diminished Virtual erect enlarged None 40. Mirrors How does a two-way mirror work? It reflects all light from both sides equally. It transmits light in one direction while reflecting most light from the other. It refracts light instead of reflecting it. It acts as a polarizer, allowing only certain wavelengths through. None 41. Mirrors An object is placed between the center of curvature (C) and the focal point (F) of a concave mirror. What will be the characteristics of the image formed? Real, inverted, and enlarged Virtual, erect, and enlarged Real, inverted, and diminished No image is formed None 42. Mirrors When an object is placed at the focal point (F) of a concave mirror, what is the most likely outcome? A real, erect, and same-sized image is formed A virtual, erect, and diminished image is formed. A real, inverted, and magnified image is formed. No image is formed because the reflected rays are parallel. None 43. Mirrors Which of the following statements is true about the image formed by a concave mirror when the object is placed between the focal point (F) and the mirror? The image is virtual, erect, and magnified No image is formed because light rays do not reflect. The image is real, erect, and the same size as the object. The image is real, inverted, and diminished None 44. Mirrors An object is placed beyond the center of curvature (C) of a concave mirror. What will be the characteristics of the image formed? Real, inverted, and diminished No image is formed Virtual, erect, and magnified Real, erect, and enlarged None 45. Mirrors The image formed by a convex mirror is least likely to be? Lateral Inverted Diminished Virtual Erect None 46. Mirrors Which of the following is least likely to describe the image formed when an object is placed between the focal point (F) and the mirror in a concave mirror? Inverted Enlarged Virtual Erect None 47. Mirrors Which of the following is most likely a correct rule when constructing ray diagrams for a concave mirror? A ray traveling parallel to the principal axis reflects through the focal point (F). All of the above. A ray passing through the focal point (F) reflects parallel to the principal axis. A ray passing through the center of curvature (C) reflects back along the same path. None 48. Mirrors An object located between the centre of curvature and the principle focus of a concave mirror is most likely? Erect Virtual Diminished Real None 49. Mirrors Which of the following is least likely to describe the image formed when an object is placed beyond the center of curvature (C) in a concave mirror? Diminished Magnified Inverted Real None 50. Aberrations Which optical aberration is most affected when a lens is tilted? Coma Chromatic aberration Spherical aberration Pincushion distortion None 51. Aberrations Which statement about mydriasis is least likely? There is decreased diffraction of light There is an increase in spherical aberration There is an increase in the Stiles-Crawford effect There is an increased depth of field None 52. Aberrations Which lens material has the lowest chromatic aberration? High-index plastic Polycarbonate Trivex Crown Glass None 53. Aberrations Which type of optical aberration is characterized by different focal points for different wavelengths of light? Chromatic aberration Coma Spherical aberration Astigmatism None 54. Aberrations Which of the following statements about dispersion and chromatic aberration is most likely? Blue-blocking and red-blocking sunglasses improve sharpness by eliminating part of the chromatic interval, thereby reducing chromatic abberation In the human eye, blue rays focus behind red rays Red print appears nearer than blue print when both are displayed against a black background Image sharpness is improved by chromatic aberration in the eyes of the patients with achromatopsia None 55. Aberrations Coma aberration is most commonly seen in which type of optical system? Cylindrical lenses High-index lenses On-axis point sources Off-axis point sources None 56. Aberrations Which is least likely to reduce spherical aberration? Use of stops Pantoscopic tilt Aplanatic surfaces Use of a doublet None 57. Aberrations Which of the following adaptations of the eye does not reduce spherical aberration at the retina? Iris position Variable refractive index within lens Vitreous at the posterior lens surface acting as a doublet lens Graduated corneal curvature None 58. Aberrations Which of the following lens types is most likely to cause chromatic aberration? Convex lens with high refractive index Single-element lenses made of low-dispersion glass Bifocal lenses with spherical curvature Lenses with a large aperture and a wide field of view None 59. Aberrations What is the typical effect of spherical aberration in optical lenses? The lens magnifies objects excessively at the center Light rays passing through the optical center are deflected outward Light rays from the center and edges of the lens focus at different points Color fringing occurs around the edges of the image None 60. Visual Function Which of the following is least likely a test of stereoacuity Titmus TNO Pelli-Robson Frisby None 61. Visual Function Which of the following is true about LogMar? The letter spacing is equal to one letter width A LogMAR of +1 is equal to Snellen score of 6/6 A logMAR of 0 is equal to a Snellen score of 6/60 The number of letters increases as you move down the chart None 62. Visual Function Which of the following charts can be used to assess visual acuity in a child less than 1 years old? Keeler cards Sheridan Gardner Kay pictures LogMAR None 63. Visual Function Which of the following is false about LogMAR? he row spacing is equal to the height of a letter from the row below There are five letters on each line Each letter can be assigned a score of 0.01 The letter size increases in 0..1 LogMAR steps None 64. Visual Function What is the visual acuity of a newborn? 6/24 6/200-6/60 6/60 6/18-6/6 None 65. Visual Function What visual angle is subtentendedu by a letter on the 6/6 line of a snellen chart at 6cm? 5 minutes of arc 1 minute of arc 1 second of arc 5 seconds of arc None 66. Visual Function Colour vision is tested using? TNO N-type Cardiff Ishihara None 67. Visual Function Which of the following is used to tests the visual acuity of an 18-month-old child? LogMAR Sheridan-Gardiner Cardiff cards Kay pictures None 68. Visual Function Which of the following is least likely regarding functional vision loss? Optokinetic nystagmus is absent Tunnel vision is seen Presentation is with decreased visual acuity and is more common in females Normal pupil with no RAPD None 69. Visual Function Which of the following is least likely a test of stereo acuity? worth 4-dot Titmus Frisby Cardiff cards None 70. Visual Function Which of the following tests sensory function? Prisms Titmus Bagolini glasses TNO None 71. Visual Function Which of the following tests does not asses colour vision? Pelli-Robson Hardy-Rand-Rittler Farnsworth-Munsell Ishihara None 72. Visual Function A snellen visual acuity of 20/20 is equivalent to which of the following logMAR values? 0.02 0.00 10.00 1.00 None 73. Prisms Which of the the following is least likely regarding the visual image formed by a prism? Diminished Displaced towards the apex Erect Virtual None 74. Prisms A prism deviates light by 5 cm at a distance of 1 meter. What is its prismatic power? 50 prism diopters 5 prism diopters 0.5 prism diopters 10 prism diopters None 75. Prisms Which of the following is least likely to use prisms in spectacle correction? Correction of horizontal diplopia Treatment of presbyopia Treatment of 6th nerve palsy Correction of vertical diplopia None 76. Prisms In vision therapy, prisms are most commonly used to treat which of the following conditions? Strabismus Hyperopia Astigmatism None 77. Prisms Which is most likely about the image formed by a prism? It is virtual and displaced toward the apex It is virtual and displaced towards the base It is real and displaced towards the base It is real and displaced towards the apex None 78. Prisms Which of the following least likely determines the angle of deviation of a ray of light when refracted by a prism? Refractive index of the material of which the prism is made Refracting angle of the prism Wavelength of light of the incident ray Angle of incidence of the ray None 79. Prisms One prism diopter corresponds to a deviation of how many centimeters at a distance of one meter? 5 cm 0.5 cm 1 cm 2 cm None 80. Prisms In the treatment of binocular vision disorders, what effect does using prisms in spectacles typically have on the image? It reduces the field of vision It enlarges the image significantly It shifts the image to aid fusion It causes the image to appear doubled None 81. Prisms Which of the following prisms causes 180 degrees deviation with no left-to-right transposition? Fresnel prism Wollaston prism Dove prism Porro prism None 82. Prisms Which prism causes inversion of the image without deviation or lateral transposition? Porro prism Dove prism Wollaston prism Fresnel prism None 83. Prisms Which of the following statements regarding the Prentice position is least likely? Glass prisms are traditionally held in the prentice position The angle of incidence equals the angle of emergence The incident ray is normal to one surface of the prism The deviation of light is greater in the Prentice position than in the position of minimum deviation None 84. Refraction by the Eye What is the average dioptric power of an aphakic eye? 19 22 58 43 None 85. Refraction by the Eye When does the eye reach its maximum axial length? Does not stop growing 1-3 years old 3-7 years old 13-18 years old None 86. Refraction by the Eye Which most likely describes the far point of the non-accommodated -4.00D myopic eye? The far point is 20cm anterior to the eye The far point and fovea are conjugate points, , The far point is 25cm posterior to the eye The far point is nearer to the eye than is the point of focus of the fully accommodated eye. None 87. Refraction by the Eye What is the size of the adult eye? 34 mm 24 mm 28 mm 17 mm None 88. Refraction by the Eye What is the refractive index of the cornea? 1.33 1.52 1.37 1.40 None 89. Refraction by the Eye What is the radius of curvature (in mm) of the anterior surface of the cornea? 6.8 mm 5.7 mm 7.7 mm 7.0 mm None 90. Refraction by the Eye What is the total approximate refractive power of the human eye? 30D 43D 20D 60D None 91. Refraction by the Eye What is the primary cause of myopia? Corneal irregularity Reduced corneal curvature Excessive axial length Weak accommodation None 92. Refraction by the Eye What is the average axial length of an emmetropic human eye? 20 mm 26 mm 24 mm 22 mm None 93. Refraction by the Eye Which of the following best describes emmetropia? Light focuses in front of the retina without accommodation Light is scattered throughout the eye without a focal point Light focuses exactly on the retina without accommodation Light focuses behind the retina without accommodation None 94. Refraction by the Eye What happens to the eyes during the accommodative reflex? Convergence, miosis, and increased lens curvature Convergence, mydriasis, and lens flattening Divergence, miosis, and lens flattening Divergence, mydriasis, and increased lens curvature None 95. Refraction by the Eye Approximately how much of the eye's total refractive power comes from the cornea? 25% 60D 10% 43D None 96. Refraction by the Eye Which of the following is NOT part of the near triad response? Mydriasis Miosis Convergence Accommodation None 97. Refraction by the Eye A patient with an axial length of 26.5 mm is likely to have: Myopia Presbyopia Hyperopia Emmetropia None 98. Refraction by the Eye Which statement about the optical power of an infant’s eye is true? It is hyperopic due to a short axial length It has a lower refractive power than an adult’s eye It always has a myopic refractive error It has fully developed accommodation at birth None 99. Refraction by the Eye Which lens type is best suited for patients with high myopia (-10.00D and above)? Plus lenses Standard plastic lenses Bifocal lenses Aspheric high-index lenses None 100. Refraction by the Eye Which of the following is true about hyperopia (farsightedness)? The patient may accommodate to compensate for mild hyperopia Light focuses in front of the retina It requires concave lenses for correction It is associated with excessive axial length None 101. Refraction by the Eye Which of the following best describes the process of emmetropization? The gradual loss of accommodation with age The active adjustment of the eye’s axial length and refractive components during development The eye's ability to focus light using accommodation The process of correcting refractive errors using spectacles or contact lenses None 102. Refraction by the Eye Why does the cornea provide more refractive power than the lens? It has a greater curvature. It has a higher refractive index. It is thicker than the lens. It is closer to the retina. None 103. Refraction by the Eye Which previous model is Gullstrand's reduced eye a refinement of? Helmholtz Kepler Schooner Krunenberg None 104. Refraction by the Eye Based on Gullstrand's reduced eye, which of the following points is 7.08mm behind the anterior corneal surface? Nodal point Principle point Second focal point First focal point None 105. Refraction by the Eye In Gullstrand's reduced eye the, how far is the anterior focal point from the anterior cornea? 15.7 cm 17.7 mm 17.7 cm 15.7 mm None 106. Refraction by the Eye The total refractive power of Gullstrand's reduced eye when relaxed is? +58.64 diopter +55.64 diopter +50.64 diopter +60.64 diopter None 107. Refraction by the Eye Which of the following is not proven to slow myopic progression? Outdoor activity Using reading glasses Using atropine None of the above None 108. Refraction by the Eye The most likely effective power of the crystalline lens in situ is? 43 diopters 23 diopters 15 diopter 37 diopters None 109. Refraction by the Eye In a hypermetropic eye, moving a convex lens away from the eye? None of the above The effectivity of the lens is decreased The effectivity of the lens is increased The effectivity of the lens is unchanged None 110. Refraction by the Eye Which is is least likely to be true? The near point at which an object can be clearly seen when maximum accommodation is used The dioptric power of the accommodated eye is called its static refraction The amplitude of accommodation is the dioptric power difference between the eye at rest and when full accommodated The range of accommodation is the distance between the far point and near point None 111. Refraction by the Eye Which ocular structure has the highest refractive power? Vitreous humour Aqueous humour Cornea Lens None 112. Refraction by the Eye Which of the following is true about the lens? The anterior suture gas inverted Y shape The posterior suture has an inverted Y shape The lens becomes more spherical when looking at the distance The posterior capsule thins with age None 113. Refraction by the Eye A high AC/A ratio is most likely associated with? Convergence weakness Convergence excess esotropia Convergence excess exotropia Divergence excess esotropia None 114. Instruments Which optical instrument provides an upright and non-reversed image of the retina? Hruby lens Indirect ophthalmoscope + 20D lens Direct ophthalmoscope Goldman contact lens + slit lamp None 115. Instruments Which one of the following statements about the Geneva lens measure is true? It is calibrated for the refractive index of crown glass It uses three spring-loaded pins to measure the surface curvature of a lens When placed on a convex surface the central pin is extended relative to the peripheral pins It is possible to deduce the total power of a thin lens by measuring both surface powers and calculating the difference between them None 116. Instruments Which optical instrument provides an inverted and reversed image of the retina? Direct ophthalmoscope Indirect ophthalmoscope + 20D lens Goldman contact lens + slit lamp Hruby lens None 117. Instruments Looking through the inferior mirror of a Zeiss 4 mirror goniolensm you see a foreign body at 7 o'clock. Where is this foreign body in your patient? 7 O'Clock 1 O'Clock 11 O'Clock 5 O'Clock None 118. Instruments What factor would reduce your field of view when examining a patient with this instrument: A Moving closer to the patient Hyperopic patient Large pupil size Myopic patient None 119. Instruments Which of the following instruments relies on total internal reflection? Operating microscope Fibre-optic intracular illumination system Gonioscopy lens Direct ophthalmoscope None 120. Instruments Which Volk examination lenses has an image magnification factor of 0.93? 66 dioptre 60 dioptre 90 dioptre 78 dioptre None 121. Instruments Using the following instrument, your image would be: Inverted 9 DD (Disc Diameters) x20 magnified Real None 122. Instruments You examine a patient with the following instrument. Which factor affects your image size: Distance from patient Illumination Patient's refractive state Size of pupil None 123. Instruments Which type of patient cannot be examined using the following instrument: Astigmatic Aphakic Hyperopic Myopic None 124. Instruments Using this instrument how can you enhance your view of the posterior pole in a myopic patient? Ask them to keep their glasses on Use a green filter Stand further away from the patient Use a narrow beam None 125. Instruments Using this instrument how could you enhance your view of a micro-aneurysm? Use a red filter Move away from the patient Remove a myopic patients glasses Use a narrow beam None 126. Instruments The image formed by this instrument is not: Magnified Between the patient and the condensing lens Inverted Real None 127. Instruments What is the field of view achieved with this instrument? 10 degrees 25 degrees 50 degrees 60 degrees None 128. Instruments Your field of illumination is restricted by what when using this instrument? Hyperopic observer Hyperopic patient A small pupil Using a condensing None 129. Instruments Which of the following is true regarding indirect ophthalmoscopy? The image is virtual The image is erect The field of illumination is largest in myopia A +20D concave lens is required None 130. Instruments Your field of view is restricted by what when using this instrument? Small observer's pupil size Small patient's pupil size large patient's pupil size Large observer's pupil size None 131. Instruments You move the condensing lens away from a patient whilst using this instrument. You notice that this causes the image size to increases. This means the patient is: Myopic Hyperopic Emmetropic Moving their head None 132. Instruments You move the condensing lens away from a patient whilst using this instrument. You notice that the image size gets smaller. This means the patient is: Myopic Emmetropic Hyperopic Poorly dilated None 133. Instruments Which one of the following statements about the Hruby lens is incorrect? It has a power of -58.6 dioptres The retinal image formed lies within the eye of the patient It is used with its concave surface towards the observer The retinal image formed is virtual, erect and diminished None 134. Instruments which of the following indirect ophthalmoscopy lens gives the sides field of view? 15, 20, 28 , 30 d 20 D 15 D 28 D 30d None 135. Instruments Which of the following phenomenon is used in optical fibre? Total Internal Reflection Scattering Refraction Diffraction None 136. Imaging In fluorescein fungus imaging which colour is the excitation filter? Yellow Green Blue Red None 137. Imaging Which of the following properties of light is used by the scanning laser polarimeter to measure nerve fibre layer thickness? Power level Focal spot size Pulse duration Polarization None 138. Imaging A patient purchases a pair of yellow sunglasses. Which colour will be hardest to see? Yellow Blue Red Green None 139. Imaging Which of the following components is part of an optical coherence tomography (OCT) system? Split prism Beam splitter Laser light source Double pinhole None 140. Imaging In fluorescein fungus imaging which colour is the barrier filter? Yellow Red Green Blue None 141. Imaging What is the optical principle behind fundus autofluorescence imaging in retinal disease diagnosis? Fluorescence emission from lipofuscin in the retinal pigment epithelium Light scattering from retinal nerve fiber layers Reflection of blue light from the inner retina Absorption of infrared light to highlight choroidal structures None 142. Imaging Which type of light is used in Optical Coherence Tomography (OCT)? Microwave Infrared Ultraviolet X-rays None 143. Imaging Optical Coherence Tomography (OCT) primarily utilizes which principle to obtain high-resolution images of the retina? Diffraction Interference Refraction Fluorescence None 144. Imaging Which of the following best describes fluorescence in ophthalmic imaging? Scattering of light in all directions Complete absorption of light without re-emission Light absorption at one wavelength and emission at a longer wavelength Reflection of light at the same wavelength None 145. Lasers Which of the following light wavelengths can cause photokeratitis? Ultraviolet, Visible light X rays Infrared None 146. Lasers Which of the following is absorbed by haemoglobin and melanin only? Argon blue-green Diode laser PRP Frequency-doubled ND:YAG None 147. Lasers Ophthalmic lasers are under which laser safety class? 3b-4 3a-3b 2 1-2 None 148. Lasers which laser causes it principle effect through photo disruption? Cyclodiode laser Eximer laser Argon laser Nd-YAG laser None 149. Lasers Which laser causes it principle effect through photoablation? Cyclodiode laser Nd-YAG laser Eximer laser Argon laser None 150. Lasers Which of the following characteristics is a property of all ophthalmic lasers? Continuous wave operation A plasma active medium High efficiency Stimulated emission None 151. Lasers Which ophthalmic laser primarily causes its principal effect through photocoagulation? Eximer laser Argon laser Nd-YAG laser Femtosecond laser None 152. Lasers The ability of light wave from a laser to form interference fringes with another wave from the same beam, separated in time, is a measure of its? Spatial coherence Intensity Directionality Temporal coherence None 153. Lasers What is the primary mechanism of the femtosecond laser in cataract surgery? Photoablation Thermal coagulation Photodisruption Photocoagulation None 154. Lasers Which laser emits light at a wavelength of 1064 nm? Nd:YAG laser Diode laser Argon laser Excimer laser None 155. Lasers Which laser is commonly used for selective laser trabeculoplasty (SLT) in open-angle glaucoma? Excimer laser Diode laser Argon laser Nd:YAG laser None 156. Lasers Which laser is primarily used for panretinal photocoagulation (PRP) in diabetic retinopathy? Argon laser Nd:YAG laser Femtosecond laser Excimer laser None 157. Lasers During retinal photocoagulation, which mechanism primarily leads to therapeutic tissue effects? Photoablation Photochemical reaction Photothermal reaction Photodisruption None 158. Lasers Which optical principle is primarily responsible for the effect of laser photocoagulation in retinal surgery? Reflection of laser light causing retinal coagulation Dispersion of light within the vitreous to induce therapeutic heating Absorption of laser energy leading to a photothermal effect Refractive focusing of the laser to create a photomechanical disruption None 159. Cataract Surgery How do accommodating IOLs attempt to restore dynamic near vision? Utilize a pinhole effect to improve near vision Split light into multiple focal points for simultaneous viewing Change curvature dynamically to alter refractive power Shift anteriorly and posteriorly in response to ciliary muscle contraction None 160. Cataract Surgery Which of the following statements correctly describes the relationship between IOL power, axial length and corneal power? The IOL power should increase as the power of the cornea increases and axial length decreases The IOL power should increase as the power of the cornea increases and axial length increases The IOL power should ncrease as the power of the cornea decreases and axial length increases The IOL power should increase as the power of the cornea decreases and axial length decreases None 161. Cataract Surgery Why is no anterior chamber depth (ACD) measurement used in the SRK equation? Postoperative ACD is not necessarily the same as preoperative ACD The SRK was designed to eliminate the need for ACD Modern IOLs are all designed to have the same AC Regression analysis did not show increased accuracy when ACD was included in the SRK formula None 162. Cataract Surgery Which laser is commonly used for posterior capsulotomy after cataract surgery? Excimer laser Femtosecond laser Argon laser Nd:YAG laser None 163. Cataract Surgery Which parameter is least likely to be needed to calculate IOL power before cataract surgery? Central corneal thickness Amount of LASIK treatment Postoperative topography measurements Preoperative refraction None 164. Cataract Surgery Which value is not required in the SRK formula for intraocular lens calculation? Anterior chamber depth Axial length A-constant for the desired IOL Average keratometry reading None 165. Cataract Surgery In a patient with LASIK, which change introduces the most error in the IOL calculations? Anterior chamber depth Axial length Corneal curvature measurements High-order aberrations None 166. Cataract Surgery Which optical phenomenon is most commonly affected by the presence of a cataract? Enhanced night vision due to lens opacification Reduction in axial length, leading to myopic shift Increased light scatter and decreased contrast sensitivity Improved near vision due to reduced corneal astigmatism None 167. Cataract Surgery What optical property of ultrasound waves is essential for phacoemulsification? Refraction of light waves within the lens nucleus enhances fragmentation Chromatic dispersion separates nuclear layers for better emulsification Infrared absorption creates controlled thermal energy to emulsify the lens High-frequency sound waves induce cavitation and lens fragmentation None 168. Cataract Surgery Which optical change is commonly observed after cataract removal? Myopic shift due to corneal steepening Reduced intraocular light scatter and improved night vision Hyperopic shift due to loss of the crystalline lens power Increased astigmatism from irregular corneal wound healing None 169. Cataract Surgery How do multifocal IOLs provide both near and distance vision correction? They induce higher-order aberrations that compensate for presbyopia They dynamically change curvature based on pupil size They use diffractive optics to split incoming light into multiple focal points They selectively absorb short wavelengths to enhance near focus None 170. Cataract Surgery What optical principle allows monovision cataract surgery to provide both near and distance vision? Increasing corneal curvature in one eye to mimic accommodation Adjusting pupil dynamics to selectively refract light Creating anisometropia by implanting different-powered IOLs in each eye Utilizing polarized light filters within IOLs to enhance focus None 171. Cataract Surgery Why do patients with large pupils often struggle with multifocal IOLs? Enhanced near vision at the expense of distance vision Reduced contrast sensitivity due to corneal light scatter Increased exposure to out-of-focus light rays, causing glare and halos Loss of peripheral vision from excessive pupil dilation None 172. Cataract Surgery What is the most critical factor when implanting a toric IOL for astigmatism correction? Ensuring a higher-powered spherical IOL to compensate for residual cylinder Selecting an IOL with a lower refractive index to minimize distortion Precise alignment of the IOL axis to match the patient's astigmatic axis Increasing corneal hydration to reduce astigmatic impact None 173. Cataract Surgery How does small incision cataract surgery (SICS) impact postoperative corneal astigmatism? Induces myopic shift due to decreased corneal thickness Shifts the astigmatic axis to a more oblique orientation Reduces corneal astigmatism by minimizing incision-induced changes Increases irregular astigmatism due to unpredictable corneal wound healing None 174. Cataract Surgery Why are some intraocular lenses designed to filter blue light? To decrease pupil constriction and increase retinal illumination To reduce phototoxic damage to the retina and improve contrast sensitivity To improve dark adaptation by blocking peripheral scatter To enhance near vision by selectively focusing shorter wavelengths None 175. Cataract Surgery How do Extended Depth of Focus (EDOF) intraocular lenses achieve a continuous range of vision? Use of chromatic aberration correction to extend focal points Pinhole optics to minimize out-of-focus blur Increased asphericity to induce controlled spherical aberrations Elimination of multiple focal points to create a single elongated focus None 176. Cataract Surgery Why might a surgeon implant a secondary (piggyback) IOL in a pseudophakic patient? To improve depth perception in monovision patients To reduce spherical aberrations caused by the first IOL To compensate for posterior capsule opacification To correct significant residual refractive error None 177. Cataract Surgery Which optical phenomenon is most likely to affect visual quality in patients with small pupils after multifocal IOL implantation? Widening of peripheral field with loss of central clarity Reduced effect of multifocal optics leading to poor near vision Increased chromatic aberration due to pupil-dependent refraction Increased depth of focus but reduced contrast sensitivity None 178. Cataract Surgery Why are negative-power IOLs sometimes required for extremely high myopia in cataract surgery? The natural crystalline lens has strong positive power, and its removal necessitates a negative correction A posteriorly placed IOL requires negative power for proper light convergence Negative lenses compensate for elongated axial length by neutralizing corneal power Negative lenses enhance retinal image magnification in myopic patients None 179. Cataract Surgery What optical aberration is most commonly induced when an IOL is significantly decentered postoperatively? Coma Spherical aberration Chromatic aberration Barrel distortion None 180. Cataract Surgery How does reverse optic capture influence refractive outcomes in IOL implantation? Pushes the IOL posteriorly to induce a hyperopic shift Increases posterior capsule opacification by trapping lens fibers Minimizes glare and halos by reducing light scatter at the IOL edge Reduces higher-order aberrations by stabilizing the IOL None 181. Cataract Surgery What optical principle contributes to positive dysphotopsia in some IOL patients? Excessive chromatic dispersion from multifocal optics Pupil-dependent refraction misalignment Internal reflection of light at the IOL edge Light scattering due to incomplete posterior capsule opacification None 182. Refractive Surgery Which of the following is not a complication of refractive eye surgery? PCO Dry eyes DLK Glare None 183. Refractive Surgery How long should soft contact lenses be withheld for before undergoing laser eye surgery? 7-14 days 14-21 days 21-28 days 28-35 days None 184. Refractive Surgery A corneal flap is created, the storm is then ablated, and the flap is replaced. what is this a description of? YAG laser capsulotomy PRK LASEK LASIK None 185. Refractive Surgery Which of the following is not an intervention for myopic correction? Central corneal ablation with LASIK Peripheral corneal ablation with LASIK Negative diopter lens Central corneal ablation with LASEK None 186. Refractive Surgery Which of the following is a key difference between PRK and LASIK? LASIK has a slower visual recovery than PRK PRK does not require a corneal flap PRK removes less corneal tissue than LASIK LASIK has a higher risk of corneal haze None 187. Refractive Surgery Which of the following is a contraindication for LASIK surgery? Keratoconus History of dry eyes Presbyopia A) Mild myopia (-2.00D) None 188. Refractive Surgery Why might a phakic IOL (ICL) be preferred over LASIK in some patients? Phakic IOLs preserve the cornea LASIK is more effective Phakic IOLs are only used in presbyopia LASIK is the only option for high myopia None 189. Refractive Surgery What is the primary advantage of SMILE (Small Incision Lenticule Extraction) over LASIK? Faster recovery Better correction of hyperopia Less risk of dry eye No need for a femtosecond laser None 190. Refractive Surgery Which instrument is the most accurate for measuring anterior chamber depth? Slit lamp with Van Herick technique Direct ophthalmoscope Pentacam (Scheimpflug imaging) Indirect ophthalmoscope None 191. Refractive Surgery Why are IOL power calculations more challenging in post-LASIK patients? The axial length is affected by previous refractive surgery The effective lens position is unpredictable due to changes in corneal biomechanics The residual epithelial thickness alters the refractive index of the cornea Corneal power is inaccurately estimated due to altered curvature None 192. Retinal Surgery Which optical phenomenon contributes to improved visualization of the retina during surgery under a microscope? Reduction of spherical aberration using coaxial illumination Enhancement of retinal contrast via polarized light filtering Total internal reflection at the vitreous-retinal interface Light scattering due to small pupil size None 193. Retinal Surgery Silicone oil in aphakic eye leads to? Hyperopic shift Myopic shift No change Blindess None 194. Retinal Surgery Why are wide-angle viewing systems preferred in modern retinal surgery? They increase image brightness by eliminating reflections from the corneal surface They reduce chromatic aberration and enhance color contrast in retinal structures They magnify the central retina, allowing for more detailed surgical precision They provide a panoramic view of the peripheral retina without requiring frequent lens adjustments None 195. Retinal Surgery Which optical property makes perfluorocarbon liquids (PFCL) useful in vitreoretinal surgery? Selective absorption of short-wavelength light, reducing phototoxicity High viscosity, preventing intraoperative turbulence Low refractive index, improving light transmission through the vitreous High specific gravity allowing mechanical flattening of the retina None 196. Retinal Surgery Which refractive change is commonly observed following pars plana vitrectomy with gas tamponade? Myopic shift Hyperopic shift Astigmatic shift No significant refractive change None 197. Retinal Surgery Which optical aberration is most commonly encountered when performing wide-field retinal imaging? Coma from off-axis light sources Distortion due to peripheral magnification differences Spherical aberration from excessive lens curvature Chromatic aberration from lens dispersion None 198. Retinal Surgery What optical principle makes endoillumination essential for vitreoretinal surgery? Total internal reflection of fiber-optic light enhances contrast High refractive index of fiber optics ensures focused light delivery Polarization reduces glare and enhances macular detail Scattering within the vitreous helps illuminate deep retinal layers None 199. Prescriptions Which bifocal segment design provides the widest near reading area? Flat-top bifocal Round-segment bifocal Progressive lens Executive bifocal None 200. Prescriptions Which of the following is an advantage of soft contact lenses over RGP lenses? Lower risk of corneal infections Higher oxygen permeability More effective in correcting keratoconus Better initial comfort None 201. Prescriptions An adult has diplopia and a left hypertrophic of 6Δ. which combination of prisms in his glasses will most likely align the two images for him? 3Δ base down (OD), 3Δ base up (OS) 6Δ base down (OD), nothing (OS) 3Δ base up(OD), 3Δ base down (OS) 4Δ base down (OD), 2Δ base down (OS) None 202. Prescriptions Which test is commonly used to measure the amplitude of accommodation? Bagolini striated lenses Maddox rod test Push-up test Worth 4-dot test None 203. Prescriptions What type of image distortion is most common with high-plus (hyperopic) lenses? Barrel distortion Coma Chromatic aberration Pincushion distortion None 204. Prescriptions What strength of lens is needed so that a patient with 20/160 visual acuity can read newsprint without accommodation? +5.00 D +10.00 D +8.00 D +12.50 D None 205. Prescriptions Which aberration is reduced by using aspheric lenses? Chromatic aberration Spherical aberration Coma Distortion None 206. Prescriptions A Maddox rod is place in front of a patient's right eye with its axis vertical. She is asked to look at a white spot and sees a horizontal red line with the light above it. What does that indicate? Exophoria Right hypophoria Esophoria Right hyperphoria None 207. Prescriptions You use the duochrome test to refine the refraction of a patient. The patient says the red letter are much clearer than the green. The patient is: Overplussed Astigmatic Anisometropic Overminused None 208. Prescriptions Which optical issue do progressive lenses correct that bifocals do not? High astigmatism Near vision Intermediate vision Distance vision None 209. Prescriptions What is the primary purpose of the Jackson Cross Cylinder (JCC) test? To determine near addition power To refine the axis and power of astigmatism To measure spherical refractive error To assess accommodation ability None 210. Prescriptions What type of patient benefits the most from myodisc lenses? High myopia Presbyopia High hyperopia Astigmatism None 211. Prescriptions What is the primary purpose of an anti-reflective coating on eyeglass lenses? To prevent all light from entering the eye To reduce glare and ghost images To create a mirror effect on the lens surface To increase light reflection for better contrast None 212. Prescriptions The base curve of a contact lens is primarily chosen based on which measurement? Anterior chamber depth Pupil size Lens diameter Central keratometry readings None 213. Prescriptions What is a key advantage of Fresnel prisms in ophthalmic use? They provide higher magnification. They do not require refraction correction. They are lightweight and flexible. They reduce chromatic aberration. None 214. Prescriptions Which function of the tear film is most critical for successful contact lens wear? Maintaining corneal hydration Creating a smooth optical surface Providing nutrients to the cornea Removing debris from the eye None 215. Prescriptions What is unique about gradient index (GRIN) lenses compared to standard lenses? They can only be used in microscopes. They have a uniform refractive index throughout the material. They work only for concave lenses. They have a continuously varying refractive index. None 216. Prescriptions In clinical practice, a Maddox rod is used to assess which of the following? Ocular alignment Intraocular pressure Color vision Visual acuity None 217. Prescriptions How does increasing the base curve radius affect a contact lens fit? It has no effect on fit. It loosens the lens fit. It tightens the lens fit. It increases the lens power. None 218. Prescriptions What is the primary effect of high-minus spectacle lenses on retinal image size? It increases magnification. It induces a prismatic shift. It has no effect on image size. It reduces image size. None 219. Prescriptions Which type of spherical lens is used to correct myopia? Concave (diverging) lens Plano-convex lens Convex (converging) lens Cylindrical lens None 220. Prescriptions Which optical phenomenon may cause double vision when a prism is incorrectly placed in spectacles? Chromatic aberration Ghosting Monocular diplopia Image displacement None 221. Prescriptions How does a pinhole improve vision in a hyperopic patient? It increases accommodation. It magnifies the image. It increases depth of focus by reducing peripheral blur. It increases the corneal curvature. None 222. Prescriptions What is the primary purpose of a retinoscope in clinical practice? To measure refractive error objectively To visualize the anterior chamber To examine the retina To assess intraocular pressure None 223. Prescriptions Which type of contact lens is most commonly used to correct aphakia? High-plus silicone hydrogel soft lens Scleral lens Rigid gas-permeable (RGP) corneal lens Hybrid lens with aspheric optics None 224. Prescriptions Which of the following is a correct transcription of a 0.50 Jackson's Cross cylinder? +0.50 DS/ -0.50 DC +0.25 DS/ -0.50 DC +0.50 DS/ -0.25 DC +0.25 DS/ -0.25 DC None 225. Prescriptions Regarding the Jackson's cross cylinder? The cylinder in the cross cylinder has twice the power of the sphere It is equivalent to two superimposed cylindrical lenses with axes at 45 degrees to each other The cross cylinder's handle is held in line with the axis of the trial cylinder The handle is traditionally in line with the axis of the negative cylinder None 226. Prescriptions Which is least likely in spectacle correction for aphakia? Pin fusion distortion Ring scotoma Image magnification Barrel distortion None 227. Prescriptions Which of the following regarding contact lenses is used in patients with dry eyes? Soft lenses Rigid lenses Monthly lenses Silicone hydrogel None 228. Prescriptions A patient is fitted with a rigid gas permeable contact lens. The average K reading is 7.67mm, and the base curve of the lens in 7.5 mm. What is the shape of the resultant tear lens? No tear lens will be formed Concave Plano Convex None 229. Prescriptions In a myopic patient, which of the following is increased with contact lens wear compared to glasses? Optical aberrations Aniseikonia Image magnification Image distortion None 230. Prescriptions Which of the following statement is correct regarding the segment choice when prescribing bifocals for a patient with hyperopia? The use of a round-top segment reduces the prismatic displacement effect and increases image jump A flat-top segment is preferred because of its thin upper edge which causes less prismatic effect The practitioner should leave the choice of the segment type to the optician, A round-top segment is preferred because it lessens image jump None 231. Prescriptions A patient with a red Maddox rod with the cylinders orientated horizontally placed over her left eye. What does she see when she views a distant white fixation light? Red light, vertical red line Red light, horizontal red line White light, horizontal red line White light, vertical red line None 232. Astigmatism Which of the following is an advantage of rigid gas permeable (RGP) contact lenses over soft lenses? Does not require lens care Greater initial comfort Reduced risk of corneal hypoxia Higher oxygen permeability None 233. Astigmatism Which type of lens is used to correct astigmatism? Plano-convex lens Prism lens Cylindrical lens Spherical lens None 234. Astigmatism In against-the-rule (ATR) astigmatism, the steepest meridian is located at approximately: 135° 180° 45° 90° None 235. Astigmatism In simple myopic astigmatism, how does light focus? Both focal points are behind the retina. One focal point is on the retina, and the other is behind the retina. One focal point is on the retina, and the other is in front of the retina. Both focal points are in front of the retina. None 236. Astigmatism What type of astigmatism is more commonly seen in older adults? Oblique astigmatism Irregular astigmatism With-the-rule astigmatism Against-the-rule astigmatism None 237. Astigmatism In a cylindrical lens, where does the full power of the lens act? Perpendicular to the axis Along the axis Evenly across the entire lens At 45° to the axis None 238. Astigmatism In a patient with regular astigmatism, how are the principal meridians positioned? Perpendicular to each other At 30-degree intervals Randomly aligned Parallel to each other None 239. Astigmatism Where does a cylindrical lens exert its refractive power? Equally across the entire lens Perpendicular to the axis of the lens Along the axis of the lens At the center of the lens None 240. Astigmatism A patient’s vision improves with a stenopaic slit placed at 90°. What type of refractive error does this suggest? Simple hyperopia Simple myopia Against-the-rule astigmatism With-the-rule astigmatism None 241. Astigmatism Which of the following is used to manage keratoconus? LASEK Rigid contact Lenses Toric lenses LASIK None 242. Astigmatism In simple hypermetropic astigmatism? Both focal lines are in front of the retina One focal line is on the retina whilst the other is behind it Both focal lines are behind the retina The focal lines are straddling the retina None 243. Astigmatism Which of the following prescriptions is an example of 'with the rule' astigmatism? +3.50 DS/ -0.75 DC axis 90 -5.25 DS/ +2.50 DC axis 180 +3.00 DS/ +2.25 DC axis 85 -1.50 DS/ -1.00 DC axis 45 None 244. Astigmatism Keratoconus most likely causes? Refractive myopia Axial hypermetropia Axial myopia Refractive hypermetropia None 245. Astigmatism If rays of light from all meridians come into focus behind the retina, this is called? Compound myopic astigmatism Simple hypermetropic astigmatism Simple myopic astigmatism Compound hypermetropic astigmatism None 246. Low Vision Aids Which low vision aid can help a patient with Age Related Macular Degeneration watch TV? Galilean telescope Magnifying glass loop magnifiers Hubble telescope None 247. Low Vision Aids What is the primary purpose of low vision aids in the management of patients with visual impairment? To restore normal vision To magnify images for clearer vision To eliminate the need for corrective lenses To treat underlying eye diseases None 248. Low Vision Aids Which of the following low vision aids is best suited for improving distance vision in individuals with low vision? Reading glasses Telescopic lenses Bifocal lenses Magnification spectacles None 249. Low Vision Aids Which of the following low vision aids is most commonly used for close-up tasks such as reading? Fresnel prisms Visual field expanders Telescopic lenses High-powered magnifying glasses None 250. Low Vision Aids Which of the following statements about the Galilean telescope is least likely? The objective and eye piece lenses are separated by the difference between their focal lengths It is composed of two convex lenses The image is typically dimmer than seen with the unaided eye It has an extremely narrow field of view None 251. Low Vision Aids What role do prisms play in binoculars? They increase the brightness of the image. They invert and erect the image. They allow light to be focused at a single point. They reduce chromatic aberration. None 252. Low Vision Aids Which of the following best describes the image produced by a Galilean telescope? Virtual, erect, magnified, at the sum of the focal lengths of the objective and eyepiece lens Virtual, inverted, magnified, at the sum of the focal lengths of the object and eyepiece lens Virtual, erect, magnified at infinity Virtual, inverted, magnified, at infinity None 253. Low Vision Aids Which optical application commonly uses a plano-convex lens? Camera telephoto lens Myopia correction Magnifying glass Optical fiber focusing None 254. Clinical Which of the following is not associated with myopia? Congenital glaucoma ROP RRD Uveal effusion syndrome None 255. Clinical Which of the following is used to distinguish between open and closed angle glaucoma? Fundoscopy Gonioscopy Perimetry Tonometry None 256. Clinical What investigation is used to measure corneal curvature? Perimetry Keratometry Tonometry Pachymetry None 257. Clinical A patient with presbyopia says he can now see without his reading glasses, Which cataract does the patient have? Nuclear sclerotic Anterior subcapsular Posterior subcapsular Cortical None 258. Clinical Which of the following structures is affected leading to presbyopia? Zonules Cornea Lens Iris None 259. Clinical Which of the following factors increases the risk of infection in a patient using extended wear contact lenses? Normal eyelid function Intact corneal epithelium Switching to daily -wear contacts Exposure to smoke None 260. Clinical Regarding the prevalence of myopia (of at least -0.5 dioptres): Myopis tends to decrease with nuclear sclerosis of the lens It is lower in adults than in young children It is high in white Europeans compared to other ethnicities Time spent outdoors as a child is a protective factor agains myopia None 261. Clinical A child has a cycloplegia refraction 0D +6.00D, OS +2.00. What is the best way to manage the anisometropia? Full correction Paleoptic therapy Occlusion therapy Partial correction None 262. Clinical Which lens can be used to examine the anterior chamber angle? Three mirror lens Hruby lens 90D lens Wide field lens None 263. Clinical Which of the following indirect ophthalmoscopy lenses gives the greater magnification? 20 D 28 D 15 D 30 D None 264. Clinical How does corneal edema primarily affect vision? Increases light scatter Causes hyperopia Enhances contrast sensitivity Induces myopia None 265. Clinical Which of the following is a common optical correction for presbyopia? Cylindrical lenses Plano convex lenses Progressive addition lenses (PALs) Single-vision myopic glasses None 266. Clinical What is the primary cause of presbyopia? Loss of lens elasticity Corneal steepening Increase in axial length Weakening of the extraocular muscles None 267. Clinical Which factor is least likely to influence the onset of presbyopia? Refractive error Gender Geographic location Age None 268. Spherical Lenses How is the image formed by a convex lens of an object located inside the first focal point best described? Erect, virtual, further from lens than object, magnified Erect, real, inside age second focal point, diminished Inverted, real, outside the second focal point, magnified Inverted, virtual, at infinity, diminished None 269. Spherical Lenses What role does a concave lens play in a Keplerian telescope? It magnifies the image without altering the focal length It enhances color contrast by removing chromatic aberration It corrects the inverted image formed by the convex objective lens It increases the field of view while maintaining image size None 270. Spherical Lenses For a convex lens, placing an object outside the first principle focus results in an image that is Magnified, inverted, virtual Erect, real Enlarged, erect, virtual Inverted, real None 271. Spherical Lenses A higher refractive index lens has which of the following advantages? Increased lens thickness Reduced lens thickness Increased chromatic aberration Increased spherical aberrations None 272. Spherical Lenses The image formed by a thin concave lens is? Real, inverted, magnified, outside the second focal point Virtual, inverted, diminished at infinity Virtual, erect, diminished, inside the second focal point Real erect, magnified, further from the lens than the object None 273. Spherical Lenses Tilting a spherical lens can induce which type of optical effect? Reduced power No effect Induced prism Elimination of aberrations None 274. Spherical Lenses What happens when the curvature of a spherical lens increases? The refractive index of the lens material changes The focal length increases, reducing the lens’s optical power The lens starts to behave like a prism instead of a spherical lens The focal length decreases, making the lens more powerful None 275. Spherical Lenses Which factor increases the optical power of a spherical lens, assuming the shape remains the same? Reducing the curvature of the lens surfaces Using a material with a higher refractive index Increasing the focal length of the lens Decreasing the thickness of the lens None 276. Spherical Lenses What type of image is always produced by a concave (diverging) spherical lens? Virtual, inverted, and same size as the object Real, inverted, and magnified Real, upright, and larger than the object Virtual, upright, and smaller than the object None 277. Spherical Lenses Which factor increases the optical power of a spherical lens, assuming the shape remains the same? Using a material with a higher refractive index Decreasing the thickness of the lens Increasing the focal length of the lens Reducing the curvature of the lens surfaces None 278. Spherical Lenses Which statement is true regarding the difference between a biconcave and a plano-concave lens? A plano-concave lens has equal power on both sides A plano-concave lens is used to converge light rays A biconcave lens has two concave surfaces and more negative power A biconcave lens forms only real images None 279. Spherical Lenses What happens to the focal length of a convex lens when it is submerged in water? It remains the same because focal length is a material property It increases because the refractive index contrast between the lens and water is reduced It depends only on the lens curvature, not the surrounding medium It decreases because water enhances light bending None 280. Jokes 😉 Why do people randomly test themselves for color blindness online? Because they saw a meme that convinced them they’ve been colorblind their whole life. Because it’s a convenient way to procrastinate at work. Because they want to prove their friends wrong in an argument about "blue or green?" Because they need to know whether they’d survive as a bomb defuser in an action movie. None 281. Jokes 😉 What’s the real reason optometrists get excited about astigmatism? Because prescribing cylindrical correction makes them feel like wizards. Because saying “with-the-rule astigmatism” makes them feel fancy. Because they secretly enjoy watching patients struggle with JCC testing. Because it’s a good excuse to show off their maths skills. None 282. Jokes 😉 What is the most common reaction after LASIK surgery? “Can I get a refund if I still need glasses?” “So… I paid thousands of dollars and now I have dry eyes forever?” “My vision is so clear, I can now see all my life mistakes.” “Wow, I can see! Time to read the fine print on my medical bills.” None 283. Properties of Light A beam of light passes from air into glass at an angle. What happens to its frequency? It increases. It decreases. It becomes zero. It remains the same. None 284. Properties of Light Which of the following is least likely to happen when constructing a correct ray diagram? At least two rays are required to locate an image. The image forms where the reflected or refracted rays intersect. If the rays appear to diverge, a virtual image is formed. Rays that do not intersect will eventually converge if extended. None 285. Properties of Light Destructive interference is most likely in: Refraction Corneal endothelium Corneal epithelium Antireflective lens coatings None 286. Properties of Light When light moves from air to water and travels towards the normal at the interface, which of the following is more likely to happen? The light will bend away from the normal The light will not bend at all. The light will bend towards the normal. The light will undergo total internal reflection. None 287. Properties of Light Which statement about the speed of light is correct? Light travels at the same speed in all mediums. Light speeds up when entering a denser medium. Light travels fastest in water. Light slows down when entering a denser medium. None 288. Properties of Light Which of the following terms best describes a substance which only allows the transmission of light in an incident plane aligned with its structure, by absorbing other light waves? Scattering Dichroic Mirrored birefringent None 289. Properties of Light Which of the following is most likely the correct rule for drawing a principal ray in a concave mirror ray diagram? A ray passing through the centre of curvature (C) reflects at a random angle. A ray parallel to the principal axis reflects through the center of curvature (C). A ray incident at the mirror surface always travels straight without reflection. A ray passing through the focal point (F) reflects parallel to the principal axis. None 290. Properties of Light Which change is most likely when a ray of light passes into a denser medium? Frequency and plane Velocity only Velocity and frequency Velocity and plane None 291. Properties of Light Which definition most likely describes radiant flux? The amount of light reflected from a surface The intensity if light emitted from a source The amount of light emitted from a source The amount of light falling in a surface None 292. Properties of Light The image of an object formed by reflection at a plane surface is least likely to be? Diminished Erect Virtual Laterally inverted None 293. Properties of Light How is surface illumination related to the distance from the light source? Inversely proportional Directly proportional to the square root Directly proportional Inversely proportional the square root None 294. Properties of Light Regarding optical radiation, which of the following is least likely? Shorter wavelengths undergo increased scatter Light emitted through fluorescence typically has a longer wavelength than the excitation light that trigger it The energy of a photon is directly proportional to its wavelength The wavelength of light decreases as it enters a transparent material from a vacuum None 295. Properties of Light What causes the appearance of a secondary rainbow? Diffraction of light waves A change in the sun’s intensity Multiple internal reflections inside raindrops A different type of water droplet composition None 296. Properties of Light Wavelength is best defined as? One complete oscillation The distance between two symmetrical parts of the wave motion Any portion of the cycle The maximum displacement of an imaginary particle on the wave from the baseline None 297. Properties of Light What type of reflection occurs on a rough surface? Diffuse reflection Polarized reflection Total internal reflection Specular reflection None 298. Properties of Light What does polarized light consist of? Light waves oscillating in multiple planes Light waves oscillating in a single plane Light waves with equal wavelengths Light waves with reduced intensity None 299. Properties of Light Total internal reflection occurs is most likely if the incident ray strikes the interface of media at? The critical angle An angle greater than the critical angle An angle less than the critical angle 90 degrees None 300. Properties of Light The most likely unit of illuminance is? Lux (human per square metre) Lumen Cadelas (lumen per steradian) Watts per steradian None 301. Properties of Light Which catastrophic image is most likely to form an inverted image? Add description here! Posterior lens surface Anterior lens surface Posterior corneal surface Anterior corneal surface None 302. Properties of Light Which type of light wave carries the most energy? Ultraviolet light Blue light Infrared light Red light None 303. Properties of Light Which of the following statements about convave lenses is TRUE? They always produce virtual images They cause light to diverge They converge parallel light rays to a focal point They are used to correct myopia None 304. Properties of Light Which of the following correctly describes light? It is a longitudinal wave. It requires a medium to travel. It travels at the same speed in all materials. It can exhibit both wave and particle properties. None 305. Properties of Light Which of the following factors affects the scattering of light in the eye? Corneal thickness Lens elasticity Wavelength of light Intraocular pressure None 306. Properties of Light What is the main law governing the reflection of light? Fermat’s Principle Snell’s Law Law of Equal Angles Brewster’s Law None 307. Properties of Light What happens to light as it moves from a less dense medium (air) to a denser medium (cornea)? It remains unaltered It slows down and bends toward the normal It bends away from the normal It speeds up None 308. Properties of Light Which of the following pairs is matched correctly? Refractive index-meters per second Wavelength-nanometers Prism diopter-meters per centimetre Dioptre-meter None 309. Properties of Light Which of the following statements about convex lenses is TRUE? They cause light to diverge They always produce virtual images They are used to correct myopia They converge parallel light rays to a focal point None 310. Properties of Light Which optical principle explains the formation of mirages? Reflection Diffraction Refraction Dispersion None 311. Properties of Light Which color of visible light has the shortest wavelength? Green Blue Red Yellow None 312. Properties of Light When the angle of incidence is greater than the critical angle? Total Internal reflection occurs Total external refraction occurs The angle of incidence cannot be greater than the critical angle Reflection mostly occurs with some refraction None Please fill in the comment box below. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time's up
