Complete Diagnostic Optics ophthalmology MCQs online (Q361–400) covering Autorefraction, Wavefront Aberrometry, Hartmann-Shack sensors, Corneal Topography, Pentacam, Scheimpflug imaging, and higher-order aberrations. Fully explained answers ideal for NEET PG, NEXT, AIIMS, and Optometry and Ophthalmology exam preparation.
Autorefraction & Objective Refraction Devices
Q361. Autorefractor works on the principle of —
A. Infra-red reflection from retina
B. Laser diffraction
C. Refraction through cornea
D. Wavefront scattering
View Answer
A. Infra-red reflection from retina ✅ Exp: Infrared light reflected from retina analyzed for refractive error.
Q362. Autorefractor provides —
A. Objective refraction data
B. Subjective endpoint
C. Binocular vision test
D. Muscle balance test
View Answer
A. Objective refraction data ✅ Exp: Quick estimation before subjective refinement.
Q363. Limitation of autorefractor —
A. Overestimates myopia in accommodation
B. Cannot detect astigmatism
C. Slow to use
D. Requires dilation always
View Answer
A. Overestimates myopia in accommodation ✅ Exp: Active accommodation in young patients affects readings.
Q364. Infra-red light is used because —
A. Not perceived by retina
B. Strongly focused
C. Polarized
D. Reflected by lens only
View Answer
A. Not perceived by retina ✅ Exp: Avoids accommodation and glare.
Q365. Handheld autorefractor useful in —
A. Children and bedridden patients
B. Myopic adults only
C. Corneal opacity
D. Pseudophakia
View Answer
A. Children and bedridden patients ✅ Exp: Portable and convenient for screening.
Q366. Autorefractor output includes —
A. Sphere, cylinder, and axis
B. Visual acuity
C. IOP
D. Field chart
View Answer
A. Sphere, cylinder, and axis ✅ Exp: Gives full refractive prescription in objective form.
ophthalmology mcqs online
Q367. Cycloplegia improves accuracy of —
A. Autorefraction
B. Subjective refraction
C. Perimetry
D. Fundus exam
View Answer
A. Autorefraction ✅ Exp: Eliminates accommodation effects in young patients.
Q368. Retinoscopy and autorefractor readings may differ due to —
A. Accommodation & pupil size
B. Tear film
C. Age only
D. Iris color
View Answer
A. Accommodation & pupil size ✅ Exp: Subjective control and fixation stability matter.
Q369. Infrared wavelength used in autorefractor —
A. 800–900 nm
B. 400–500 nm
C. 600 nm
D. 1000–1100 nm
View Answer
A. 800–900 nm ✅ Exp: Near-infrared for minimal visual stimulation.
Q370. Autorefractor accuracy reduced in —
A. Media opacities
B. Hyperopia
C. Myopia
D. Presbyopia
View Answer
A. Media opacities ✅ Exp: Cataract scatters IR light, reducing reflection.
Q371. Corneal topography based on —
A. Placido disc reflection
B. Interferometry
C. Refraction only
D. Diffraction
View Answer
A. Placido disc reflection ✅ Exp: Analyzes pattern of concentric rings reflected from corneal surface.
Q372. Topography measures —
A. Curvature and elevation of cornea
B. Thickness
C. Tear film
D. Endothelial count
View Answer
A. Curvature and elevation of cornea ✅ Exp: Gives curvature maps in diopters and microns.
Q373. Corneal topography is useful in —
A. Keratoconus diagnosis
B. Cataract grading
C. Glaucoma staging
D. Vitreous opacities
View Answer
A. Keratoconus diagnosis ✅ Exp: Detects irregular astigmatism and ectasia.
Q374. Color-coded corneal map —
A. Warm colors = steep areas
B. Cool colors = steep areas
C. Blue = high curvature
D. Yellow = flat
View Answer
A. Warm colors = steep areas ✅ Exp: Red/orange areas represent high curvature.
Q375. Simulated keratometry (Sim-K) readings from topography represent —
A. Central corneal curvature
B. Peripheral zones
C. Posterior surface
D. Average refractive index
View Answer
A. Central corneal curvature ✅ Exp: Equivalent to manual keratometry values.
Q376. Corneal topographer cannot measure —
A. Posterior corneal surface
B. Central 3 mm
C. Peripheral flattening
D. Axis orientation
View Answer
A. Posterior corneal surface ✅ Exp: Reflection-based system sees anterior only
Q377. Scheimpflug imaging principle —
A. Slit-beam cross-sectional photography
B. Reflection analysis
C. Ultrasound
D. Fluorescence
View Answer
A. Slit-beam cross-sectional photography ✅ Exp: Provides 3D image of cornea and anterior chamber.
ophthalmology mcqs online
Q378. Scheimpflug system measures —
A. Corneal thickness & curvature
B. Pupil reaction
C. Retinal contour
D. Vitreous depth
View Answer
A. Corneal thickness & curvature ✅ Exp: Used for pachymetry and anterior segment analysis.
Q379. Corneal tomography differs from topography by —
A. Measuring both anterior & posterior surfaces
B. Using visible light
C. Measuring only curvature
D. Excluding thickness
View Answer
A. Measuring both anterior & posterior surfaces ✅ Exp: Provides elevation-based 3D mapping.
Q380. Pentacam uses —
A. Rotating Scheimpflug camera
B. Placido disc
C. Laser interferometer
D. Optical coherence
View Answer
A. Rotating Scheimpflug camera ✅ Exp: Combines slit-scanning and rotation for detailed imaging.
Q381. Wavefront aberrometer measures —
A. Optical aberrations of entire eye
B. Only corneal curvature
C. Retinal thickness
D. Lens power
View Answer
A. Optical aberrations of entire eye ✅ Exp: Evaluates total optical performance.
ophthalmology mcqs online
Q382. Wavefront principle based on —
A. Light ray deviation from ideal plane
B. Prism deviation
C. Refraction angle
D. Chromatic dispersion
View Answer
A. Light ray deviation from ideal plane ✅ Exp: Measures deviation of emerging wavefronts from a perfect sphere.
Q383. Hartmann-Shack sensor used in —
A. Wavefront aberrometry
B. OCT
C. Keratometry
D. Tonometry
View Answer
A. Wavefront aberrometry ✅ Exp: Array of microlenses detects local wavefront slopes.
Q384. Zernike polynomials used to —
A. Describe optical aberrations mathematically
B. Calculate diopters
C. Determine field of view
D. Measure contrast
View Answer
A. Describe optical aberrations mathematically ✅ Exp: Quantify higher-order aberrations systematically.
Q385. Higher-order aberrations include —
A. Coma and spherical aberration
B. Astigmatism
C. Myopia
D. Hyperopia
View Answer
A. Coma and spherical aberration ✅ Exp: Complex deviations beyond simple refractive errors.
Q386. Lower-order aberrations include —
A. Myopia, hyperopia, and astigmatism
B. Coma and trefoil
C. Spherical aberration
D. Chromatic errors
View Answer
A. Myopia, hyperopia, and astigmatism ✅ Exp: Correctable by spectacles or contact lenses.
Q387. Wavefront-guided LASIK customized to —
A. Correct higher-order aberrations
B. Flatten cornea
C. Reduce pupil size
D. Increase contrast
View Answer
A. Correct higher-order aberrations ✅ Exp: Tailored ablation pattern based on measured wavefront error.
Q388. Root mean square (RMS) value in wavefront —
A. Quantifies total aberration magnitude
B. Measures light intensity
C. Indicates refractive power
D. Pupil size
View Answer
A. Quantifies total aberration magnitude ✅ Exp: Numerical summary of optical imperfection.
Q389. Wavefront-guided surgery advantage —
A. Better contrast and night vision
B. Shorter healing
C. Lower cost
D. Thicker flap
View Answer
A. Better contrast and night vision ✅ Exp: Reduces glare and improves visual quality.
ophthalmology mcqs online
Q390. Aberrometry data represented as —
A. Color-coded map
B. Black-white graph
C. Line chart
D. Histogram
View Answer
A. Color-coded map ✅ Exp: Shows aberration pattern across pupil area.
Q391. Wavefront aberrometry useful in —
A. LASIK planning & postoperative analysis
B. IOP measurement
C. Visual field
D. Color vision
View Answer
A. LASIK planning & postoperative analysis ✅ Exp: Detects residual or induced aberrations.
Q392. Corneal aberrometry differs from ocular aberrometry —
A. Measures cornea only
B. Excludes pupil
C. Includes retina
D. Based on ultrasound
View Answer
A. Measures cornea only ✅ Exp: Anterior surface aberrations isolated.
Q393. Common cause of increased higher-order aberrations —
A. Large pupil in dim light
B. Small pupil
C. Corrected ametropia
D. Clear media
View Answer
A. Large pupil in dim light ✅ Exp: Peripheral rays increase optical distortions.
Q394. Spherical aberration increases with —
A. Pupil size
B. Corneal thickness
C. Lens opacity
D. Accommodation
View Answer
A. Pupil size ✅ Exp: Peripheral rays refract more, enhancing blur.
Q395. Coma aberration produces —
A. Comet-shaped images
B. Radial blur
C. Uniform haze
D. Shadow lines
View Answer
A. Comet-shaped images ✅ Exp: Off-axis light rays form asymmetric tail.
Q396. Trefoil aberration causes —
A. Triangular distortion pattern
B. Radial blur
C. Astigmatic blur
D. Barrel distortion
View Answer
A. Triangular distortion pattern ✅ Exp: Three-lobed symmetrical error pattern.
Q397. Internal ocular aberrations mainly from —
A. Crystalline lens
B. Retina
C. Iris
D. Cornea only
View Answer
A. Crystalline lens ✅ Exp: Lens contributes dynamic aberrations during accommodation.
Q398. Ocular aberrometry data aids in —
A. Customized IOL design
B. Refraction only
C. Keratometry
D. Tonometry
View Answer
A. Customized IOL design ✅ Exp: Improves optical performance post-surgery.
Q399. Pupil size in aberrometry —
A. Affects measurement accuracy
B. Irrelevant
C. Alters retinal reflection only
D. Constant factor
View Answer
A. Affects measurement accuracy ✅ Exp: Larger pupils expose more aberration zones.
ophthalmology mcqs online
Q400. Wavefront-based IOLs designed to —
A. Minimize higher-order aberrations
B. Increase field
C. Reduce weight
D. Enhance color
View Answer
A. Minimize higher-order aberrations ✅ Exp: Aspheric designs compensate optical defects for better contrast.
