Complete Q321–360 ophthalmology mcq quiz on laser physics, optical coherence, OCT (TD/SD/SS), fundus camera, fluorescein angiography, ICG & imaging systems from A.K. Khurana’s Optics of Lenses & Ophthalmic Instruments. Fully accurate, non-repetitive and exam-level for NEET PG, NEXT, AIIMS & Optometry. View More Ophthalmology and Optometry MCQ
Q321. LASER stands for —
A. Light Amplification by Stimulated Emission of Radiation
B. Light Absorption and Stimulated Emission Reaction
C. Low Amplitude Stimulated Emission Radiation
D. Light Attenuation System Emission Reflection
View Answer
A. Light Amplification by Stimulated Emission of Radiation ✅ Exp: Laser light is produced by stimulated emission and optical amplification.
Q322. Stimulated emission occurs when —
A. Incident photon induces another photon of same energy
B. Electron absorbs photon
C. Random photon release
D. Thermal emission
View Answer
A. Incident photon induces another photon of same energy ✅ Exp: Both photons are identical in phase, frequency and direction.
Q323. Population inversion means —
A. More atoms in excited state than ground state
B. All atoms in ground state
C. Equal energy levels
D. Thermal equilibrium
View Answer
A. More atoms in excited state than ground state ✅ Exp: Essential for laser action to sustain stimulated emission.
Q324. Optical resonator in laser consists of —
A. Two mirrors forming cavity
B. Single lens
C. Prism pair
D. Optical fiber
View Answer
A. Two mirrors forming cavity ✅ Exp: Amplifies light by multiple reflections within gain medium.
Q325. Laser beam characteristics include all except —
A. Monochromatic
B. Coherent
C. Highly divergent
D. Collimated
View Answer
C. Highly divergent ✅ Exp: Laser beams are highly directional with minimal divergence.
Q326. Helium-Neon laser emits light at —
A. 632.8 nm
B. 530 nm
C. 400 nm
D. 700 nm
View Answer
A. 632.8 nm ✅ Exp: Red light commonly used for visual aiming and alignment.
Q327. Nd:YAG laser wavelength —
A. 1064 nm
B. 532 nm
C. 400 nm
D. 780 nm
View Answer
A. 1064 nm ✅ Exp: Infra-red light used for capsulotomy and iridotomy.
Q328. Argon laser wavelength —
A. 488 & 514 nm
B. 808 nm
C. 630 nm
D. 450 nm
View Answer
A. 488 & 514 nm ✅ Exp: Blue-green visible light absorbed by melanin and hemoglobin.
Q329. Diode laser is based on —
A. Semiconductor junction
B. Gas discharge
C. Crystal lattice
D. Liquid medium
View Answer
A. Semiconductor junction ✅ Exp: Compact, portable, widely used in photocoagulation and iridotomy.
Q330. Excimer laser used in LASIK has wavelength —
A. 193 nm
B. 532 nm
C. 630 nm
D. 1064 nm
View Answer
A. 193 nm ✅ Exp: Argon-Fluoride laser in ultraviolet range for photoablation.
ophthalmology mcq quiz Optical Physics
Q331. Photocoagulation laser works by —
A. Thermal coagulation
B. Photochemical reaction
C. Photoablation
D. Photodisruption
View Answer
A. Thermal coagulation ✅ Exp: Heat causes protein denaturation in retinal tissue.
Q332. Photoablation used in LASIK works by —
A. Breaking molecular bonds
B. Thermal melting
C. Mechanical cutting
D. Electrolysis
View Answer
A. Breaking molecular bonds ✅ Exp: Removes tissue precisely without thermal damage.
Q333. Photodisruption as in Nd:YAG laser creates —
A. Plasma and shock wave
B. Thermal burn
C. Chemical reaction
D. Scarring
View Answer
A. Plasma and shock wave ✅ Exp: Instantaneous localized disruption of tissue.
Q334. Selective photothermolysis used in —
A. Laser trabeculoplasty
B. Photocoagulation
C. Photodisruption
D. Thermal ablation
View Answer
A. Laser trabeculoplasty ✅ Exp: Targets melanin in trabecular meshwork to improve outflow.
Q335. Main hazard of laser to eye —
A. Retinal burn
B. Lens opacification
C. Corneal scar
D. Conjunctival injury
View Answer
A. Retinal burn ✅ Exp: High-energy beams focused on retina cause permanent damage.
Q336. Argon laser used for —
A. Retinal photocoagulation
B. Capsulotomy
C. Iridotomy
D. Corneal ablation
View Answer
A. Retinal photocoagulation ✅ Exp: Used for diabetic retinopathy and retinal tears.
Q337. Nd:YAG laser used for —
A. Posterior capsulotomy
B. Retinal tear
C. Trabeculoplasty
D. Photocoagulation
View Answer
A. Posterior capsulotomy ✅ Exp: Disrupts posterior capsule after cataract surgery.
Q338. Diode laser used for —
A. Panretinal photocoagulation
B. LASIK
C. Keratoplasty
D. Iridectomy
View Answer
A. Panretinal photocoagulation ✅ Exp: Efficient for retinal vascular lesions.
Q339. Excimer laser used in —
A. LASIK and PRK
B. Iridotomy
C. Trabeculoplasty
D. Gonioscopy
View Answer
A. LASIK and PRK ✅ Exp: Reshapes cornea by ultraviolet photoablation.
Q340. Femtosecond laser used for —
A. Corneal flap creation
B. Posterior capsulotomy
C. Retinal tear
D. Photocoagulation
View Answer
A. Corneal flap creation ✅ Exp: Creates precise corneal incisions in LASIK and cataract surgery.
ophthalmology mcq quiz Optical Physics
Q341. YAG peripheral iridotomy performed in —
A. Angle-closure glaucoma
B. Open-angle glaucoma
C. Cataract
D. Myopia
View Answer
A. Angle-closure glaucoma ✅ Exp: Creates alternative path for aqueous flow.
Q342. Laser trabeculoplasty indicated in —
A. Open-angle glaucoma
B. Angle closure
C. Aphakia
D. Keratitis
View Answer
A. Open-angle glaucoma ✅ Exp: Improves aqueous outflow via trabecular meshwork stimulation.
Q343. Laser capsulotomy contraindicated when —
A. Active uveitis present
B. Stable posterior capsule
C. Pseudophakia
D. PCO
View Answer
A. Active uveitis present ✅ Exp: Inflammation may worsen post-procedure.
Q344. Energy of laser pulse measured in —
A. Joules
B. Watts
C. Ergs
D. Lumens
View Answer
A. Joules ✅ Exp: Energy = power × time.
Q345. Power of continuous laser beam in —
A. Watts
B. Joules
C. Lux
D. Candela
View Answer
A. Watts ✅ Exp: Rate of energy delivery per second.
Q346. Pulse duration in Q-switched laser ≈ —
A. Nanoseconds
B. Microseconds
C. Milliseconds
D. Seconds
View Answer
A. Nanoseconds ✅ Exp: Extremely short pulses produce high peak power.
Q347. Thermal relaxation time concept important in —
A. Selective photothermolysis
B. Photoablation
C. Photocoagulation
D. Photodisruption
View Answer
A. Selective photothermolysis ✅ Exp: Time needed for tissue to dissipate heat between pulses.
Q348. OCT is based on —
A. Low-coherence interferometry
B. Refraction
C. Reflection only
D. Diffraction
View Answer
A. Low-coherence interferometry ✅ Exp: Uses interference of back-scattered light for cross-sectional images.
Q349. Light source in OCT —
A. Broadband super-luminescent diode
B. Laser diode
C. Halogen lamp
D. LED tube
View Answer
A. Broadband super-luminescent diode ✅ Exp: Provides low-coherence infra-red light (~840 nm).
Q350. Time-domain OCT differs from spectral-domain by —
A. Moving reference mirror
B. Stationary detector
C. Slower scanning
D. No interferometry
View Answer
A. Moving reference mirror ✅ Exp: TD-OCT uses mechanical mirror for depth information.
ophthalmology mcq quiz Optical Physics
Q351. Spectral-domain OCT advantage —
A. Higher speed and resolution
B. Lower sensitivity
C. Manual alignment
D. More motion artifacts
View Answer
A. Higher speed and resolution ✅ Exp: Simultaneous depth capture from spectral analysis.
Q352. Swept-source OCT uses —
A. Tunable laser
B. Fixed wavelength
C. Prism dispersion
D. Rotating mirror
View Answer
A. Tunable laser ✅ Exp: Sweeps wavelength rapidly for deep penetration (OCT-A).
Q353. Main use of OCT in retina —
A. Macular and optic nerve imaging
B. Corneal topography
C. Lens curvature
D. Aqueous depth
View Answer
A. Macular and optic nerve imaging ✅ Exp: Detects macular edema, ERM, CNVM, and optic disc changes
Q354. OCT resolution depends on —
A. Source bandwidth
B. Axial length
C. Pupil size
D. Refractive index
View Answer
A. Source bandwidth ✅ Exp: Wider bandwidth = better axial resolution.
Q355. OCT uses light wavelength of —
A. ~840 nm
B. 532 nm
C. 1064 nm
D. 400 nm
View Answer
A. ~840 nm ✅ Exp: Infra-red light for deep retinal penetration without scatter.
Q356. Fundus camera principle —
A. Reflex free imaging
B. Direct reflection
C. Magnified contact image
D. Transillumination
View Answer
A. Reflex free imaging ✅ Exp: Illumination and observation paths separated by mirror system.
Q357. Fluorescein angiography excitation filter —
A. Blue (465–490 nm)
B. Green
C. Red
D. Yellow
View Answer
A. Blue (465–490 nm) ✅ Exp: Excites sodium fluorescein dye for emission at 520–530 nm.
Q358. Emission filter in FFA —
A. Yellow-green (520–530 nm)
B. Blue
C. Red
D. Infra-red
View Answer
A. Yellow-green (520–530 nm) ✅ Exp: Blocks excitation light and transmits fluorescence.
Q359. Indocyanine Green Angiography (ICG) uses —
A. Infra-red light (~805 nm)
B. Blue light
C. UV light
D. Green light
View Answer
A. Infra-red light (~805 nm) ✅ Exp: Better for choroidal circulation imaging.
Q360. Main advantage of ICG over FFA —
A. Choroidal visualization
B. Retinal artery detail
C. Macular resolution
D. Color contrast
View Answer
A. Choroidal visualization ✅ Exp: Infra-red penetrates pigment epithelium and blood.
ophthalmology mcq quiz Optical Physics
