Ak khurana ophthalmology mcq pdf on Ophthalmic Instruments (Direct & Indirect Ophthalmoscope, Slit Lamp, Gonioscope, Operating Microscope) covering optics, magnification, illumination, field of view, and clinical applications — high-yield, exam-focused questions from Khurana Q161–200. More Ophthalmology Mcq
Ak khurana ophthalmology mcq pdf Direct Ophthalmoscope
Q161. Direct ophthalmoscope works on the principle of:
A. Total internal reflection
B. Optical coaxial illumination
C. Prism deviation
D. Diffraction
View Answer
B. Optical coaxial illumination ✅ Exp: Light and observation beams are coaxial, enabling retinal visualization through a small pupil.
Q162. Image formed by direct ophthalmoscope is:
A. Real, inverted
B. Virtual, erect
C. Real, magnified
D. Virtual, inverted
View Answer
B. Virtual, erect ✅ Exp: It produces an erect, virtual, magnified image of the fundus.
Q163. Approximate magnification in direct ophthalmoscopy is:
A. 5×
B. 15×
C. 2×
D. 25×
View Answer
B. 15× ✅ Exp: Magnification = about 15× for an emmetropic eye.
Q164. The effective field of view in direct ophthalmoscopy ≈
A. 80°
B. 6–10°
C. 20°
D. 45°
View Answer
B. 6–10° ✅ Exp: Small field but high magnification — best for macula and disc.
Q165. Image brightness in direct ophthalmoscope depends on:
A. Pupil size
B. Lens power
C. Axial length
D. Corneal curvature
View Answer
A. Pupil size ✅ Exp: Larger pupil → more light entry → brighter image.
Q166. The illumination system of a direct ophthalmoscope uses:
A. Concave mirror with central aperture
B. Plane mirror
C. Prism reflection
D. Lens combination
View Answer
A. Concave mirror with central aperture ✅ Exp: Central aperture allows viewing through reflected beam.
Q167. The red-free filter in ophthalmoscope helps visualize:
A. Retinal vessels and hemorrhages
B. Optic disc only
C. Vitreous floaters
D. Macular pigment
View Answer
A. Retinal vessels and hemorrhages ✅ Exp: Green filter enhances contrast of blood-containing structures.
Q168. The cobalt blue filter is used to:
A. Detect corneal abrasions with fluorescein
B. Measure cup–disc ratio
C. Assess macular edema
D. Reduce glare
View Answer
A. Detect corneal abrasions with fluorescein ✅ Exp: Excites fluorescein dye for epithelial defect detection.
Q169. The focusing wheel in a direct ophthalmoscope corrects for:
A. Examiner or patient refractive error
B. Corneal astigmatism
C. Lens aberrations
D. Retinal pathology
View Answer
A. Examiner or patient refractive error ✅ Exp: Adjusts vergence of observing beam for clear fundus view.
Q170. Main disadvantage of direct ophthalmoscope:
A. Small field of view
B. High cost
C. Complex optics
D. No magnification
View Answer
A. Small field of view ✅ Exp: Provides limited retinal area compared to indirect method.
Ak khurana ophthalmology mcq pdf
Q171. Indirect ophthalmoscope uses:
A. Condensing lens with head mirror illumination
B. Prism system
C. Microscope optics
D. Slit-lamp base
View Answer
A. Condensing lens with head mirror illumination ✅ Exp: Uses a strong convex (20 D) lens to form an aerial image.
Q172. Image in indirect ophthalmoscopy is:
A. Real, inverted, and reversed
B. Virtual, erect
C. Real, upright
D. Virtual, reversed
View Answer
A. Real, inverted, and reversed ✅ Exp: Image formed between lens and observer — real and inverted.
Q173. Magnification in indirect ophthalmoscopy ≈
A. 15×
B. 5×
C. 10×
D. 20×
View Answer
B. 5× ✅ Exp: Lower magnification but wide field (25–40°).
Q174. Field of view in indirect ophthalmoscopy ≈
A. 6–10°
B. 25–40°
C. 10–15°
D. 60°
View Answer
B. 25–40° ✅ Exp: Wide retinal visualization.
Q175. Indirect ophthalmoscopy uses which lens power most commonly?
A. +10 D
B. +20 D
C. +30 D
D. +15 D
View Answer
B. +20 D ✅ Exp: +20 D gives optimal balance of field and magnification.
Q176. In indirect ophthalmoscopy, the patient’s pupil must be:
A. Undilated
B. Fully dilated
C. Semi-dilated
D. Pinpoint
View Answer
B. Fully dilated ✅ Exp: Full dilation required for wide field retinal examination.
Q177. Binocular indirect ophthalmoscope provides:
A. Monocular vision
B. Stereopsis
C. No depth perception
D. Flat field
View Answer
B. Stereopsis ✅ Exp: Both eyes used → 3D depth view of retina.
Q178. Disadvantage of indirect ophthalmoscope:
A. Inverted image
B. No stereopsis
C. Small field
D. Low illumination
View Answer
A. Inverted image ✅ Exp: Image orientation reversed top-to-bottom and left-to-right.
Q179. Contact indirect ophthalmoscopy uses:
A. Goldman three-mirror lens
B. Plano-convex lens
C. Plano-concave lens
D. Slit-lamp only
View Answer
A. Goldman three-mirror lens ✅ Exp: Provides stable wide-angle fundus view through contact interface.
Q180. Indirect ophthalmoscope is preferred in:
A. Small pupils
B. Retinal detachment and peripheral lesions
C. Macular edema
D. Optic neuritis
View Answer
B. Retinal detachment and peripheral lesions ✅ Exp: Wide field allows examination of periphery.
Ak khurana ophthalmology mcq pdf
Q181. Slit lamp works on principle of:
A. Optical sectioning by focused slit of light
B. Reflection
C. Refraction
D. Diffraction
View Answer
A. Optical sectioning by focused slit of light ✅ Exp: Combines microscope + slit beam → high-resolution sectioning.
Q182. Magnification range of slit lamp:
A. 5×–10×
B. 6×–40×
C. 2×–10×
D. Fixed 20×
View Answer
B. 6×–40× ✅ Exp: Provides variable magnification depending on optics.
Q183. Illumination system of slit lamp uses:
A. Koehler illumination
B. Diffuse reflection
C. Fiber-optic tube
D. Mirror system only
View Answer
A. Koehler illumination ✅ Exp: Uniform and focused beam via slit diaphragm.
Q184. Main use of slit lamp:
A. Corneal and anterior segment evaluation
B. Fundus visualization
C. Visual field testing
D. Tear film osmolarity
View Answer
A. Corneal and anterior segment evaluation ✅
Q185. Use of fluorescein in slit-lamp exam detects:
A. Corneal epithelial defects
B. Retinal edema
C. Optic disc cupping
D. Pupil block
View Answer
A. Corneal epithelial defects ✅ Exp: Damaged epithelium stains green with cobalt blue filter.
Q186. Slit lamp with fundus lens is called:
A. Indirect ophthalmoscope
B. Fundus biomicroscope
C. Keratometer
D. Gonioscope
View Answer
B. Fundus biomicroscope ✅ Exp: Uses +90 D or +78 D lenses to view posterior segment.
Q187. For anterior chamber depth, the slit beam angle should be:
A. 10–20°
B. 45–60°
C. 80°
D. 5°
View Answer
B. 45–60° ✅ Exp: Angled beam helps visualize cornea–iris angle.
Q188. Gonioscopy helps visualize:
A. Anterior chamber angle
B. Macula
C. Lens capsule
D. Optic nerve
View Answer
A. Anterior chamber angle ✅ Exp: Uses special mirrored lenses to overcome total internal reflection at cornea–air interface.
Q189. Lens used for gonioscopy:
A. Goldman three-mirror lens
B. Plano-convex lens
C. 20 D lens
D. Cylindrical lens
View Answer
A. Goldman three-mirror lens ✅ Exp: Has mirrors angled for different zones of retina and angle structures.
Q190. Direct gonioscopy provides:
A. Upright image
B. Inverted image
C. Reversed
D. Virtual only
View Answer
A. Upright image ✅ Exp: Performed using Koeppe lens, producing erect image.
Ak khurana ophthalmology mcq pdf
Q191. Operating microscope provides:
A. Binocular stereoscopic vision
B. Monocular 2D image
C. No depth perception
D. Low illumination
View Answer
A. Binocular stereoscopic vision ✅ Exp: Both eyes view → 3D surgical visualization.
Q192. Principle of operating microscope magnification:
A. Compound lens system
B. Prism reflection
C. Mirror optics
D. Laser scanning
View Answer
A. Compound lens system ✅ Exp: Uses objective + eyepiece lenses for adjustable zoom.
Q193. Depth of focus in microscope inversely proportional to:
A. Magnification
B. Aperture
C. Distance
D. Field diameter
View Answer
A. Magnification ✅ Exp: Higher magnification reduces depth of focus.
Q194. Stereopsis in microscope achieved by:
A. Separate optical paths for each eye
B. Single lens
C. Common beam
D. Polarization
View Answer
A. Separate optical paths for each eye ✅ Exp: Binocular channels separated by prisms create depth perception.
Q195. Surgical microscope illumination is usually:
A. Coaxial
B. Oblique
C. Tangential
D. Diffuse
View Answer
A. Coaxial ✅ Exp: Coaxial light ensures shadow-free surgical field.
Q196. The term “coaxial illumination” means:
A. Observation and illumination share same axis
B. Light enters obliquely
C. Parallel illumination
D. Monocular view
View Answer
A. Observation and illumination share same axis ✅ Exp: Essential for bright, evenly lit field.
Q197. Magnification in surgical microscope usually ranges:
A. 2×–5×
B. 4×–40×
C. 10×–100×
D. 20×–80×
View Answer
B. 4×–40× ✅ Exp: Controlled via zoom optics.
Q198. The Galilean system in binoculars provides:
A. Upright image
B. Inverted image
C. Virtual image
D. Reduced field
View Answer
A. Upright image ✅ Exp: Objective and eyepiece arrangement maintains erect orientation.
Q199. A 55-year-old man presents with a sudden, painless loss of vision in one eye. Fundus examination reveals a “cherry-red spot” at the macula and a pale retina. What is the most likely diagnosis?
A. Central retinal vein occlusion
B. Central retinal artery occlusion
C. Retinal detachment
D. Age-related macular degeneration
View Answer
✅ Correct Answer: B. Central retinal artery occlusion
A “cherry-red spot” on the macula with a pale retina is characteristic of central retinal artery occlusion (CRAO). The spot represents the underlying choroidal circulation seen through the thinner fovea, while the surrounding retina appears pale due to ischemia. CRAO is an ophthalmic emergency often caused by embolism or thrombosis.
Q200. The resolving power of an optical instrument depends mainly on:
A. Wavelength and aperture
B. Lens curvature
C. Refractive index only
D. Focal length
View Answer
A. Wavelength and aperture ✅ Exp: — smaller λ, larger aperture → better resolution.
Ak khurana ophthalmology mcq pdf
