Master Physiology of Eye and Vision – Section 5: Accommodation mcq, Light/Dark Adaptation & Pupillary Reflexes with 60 high-yield MCQs and explanations. Covers accommodation reflex, presbyopia, light and dark adaptation, pupillary reactions, Argyll Robertson pupil, Adie’s pupil, and Horner’s syndrome essential for NEET PG, AIIMS, and ophthalmology mcqs for exams.
Accommodation
1. Accommodation is mediated primarily by:
A. Lens capsule
B. Ciliary muscle
C. Zonules only
D. Iris sphincter
View Answer
B. Ciliary muscle ✅ Exp: Contraction of ciliary muscle relaxes zonules → lens becomes more convex.
2. Near response triad includes:
A. Accommodation, convergence, miosis
B. Accommodation, dilation, convergence
C. Convergence, divergence, miosis
D. Accommodation, cycloplegia, dilation
View Answer
A. Accommodation, convergence, miosis ✅ Exp: Classic triad for near vision.
3. Normal amplitude of accommodation at age 10:
A. 2 D
B. 7 D
C. 14 D
D. 20 D
View Answer
C. 14 D ✅ Exp: Maximal in childhood, declines with age.
4. At age 40, average amplitude of accommodation is:
A. 10 D
B. 6 D
C. 2 D
D. 1 D
View Answer
B. 6 D ✅ Exp: Presbyopia begins as amplitude falls <5 D.
5. Presbyopia occurs due to:
A. Ciliary muscle weakness
B. Lens sclerosis & reduced elasticity
C. Zonular rupture
D. Iris atrophy
View Answer
B. Lens sclerosis & reduced elasticity ✅ Exp: Lens hardens with age.
6. The dioptric demand for reading at 25 cm is:
A. 2 D
B. 3 D
C. 4 D
D. 6 D
View Answer
C. 4 D ✅ Exp: Accommodation = 1/distance in meters (1/0.25 m = 4 D).
7. Accommodation reflex pathway involves:
A. Cortex → Edinger-Westphal nucleus → ciliary ganglion
B. Optic nerve → LGN → lateral rectus
C. Brainstem → superior colliculus → abducens
D. RPE → optic nerve → hypothalamus
View Answer
A. Cortex → Edinger-Westphal nucleus → ciliary ganglion ✅ Exp: Cortical input triggers midbrain nuclei → ciliary ganglion.
8. Cycloplegic drugs abolish accommodation by blocking:
A. Adrenergic receptors
B. Muscarinic receptors
C. Beta receptors
D. NMDA receptors
View Answer
B. Muscarinic receptors ✅ Exp: Atropine, cyclopentolate block muscarinic action in ciliary muscle.
9. Which drug stimulates accommodation?
A. Atropine
B. Pilocarpine
C. Tropicamide
D. Homatropine
View Answer
B. Pilocarpine ✅ Exp: Cholinergic agonist → ciliary contraction.
10. Paralysis of accommodation is called:
A. Cycloplegia
B. Presbyopia
C. Mydriasis
D. Hyperopia
View Answer
A. Cycloplegia ✅ Exp: Due to anticholinergic drugs or CN III palsy.
11. Light reflex pathway begins with:
A. Optic tract
B. Optic nerve → pretectal nucleus
C. Optic chiasm → LGN
D. Edinger-Westphal nucleus
View Answer
B. Optic nerve → pretectal nucleus ✅ Exp: Light input reaches pretectal nucleus.
12. Efferent pathway of light reflex:
A. CN II
B. CN III parasympathetic fibers
C. Sympathetic pathway
D. CN IV
View Answer
B. CN III parasympathetic fibers ✅ Exp: Via Edinger-Westphal → ciliary ganglion → sphincter pupillae.
13. The neurotransmitter at pupillary sphincter is:
A. Acetylcholine
B. Noradrenaline
C. Dopamine
D. Serotonin
View Answer
A. Acetylcholine ✅ Exp: ACh at muscarinic receptors contracts sphincter.
14. Direct light reflex is:
A. Constriction of ipsilateral pupil to light
B. Constriction of contralateral pupil
C. Both pupils constrict equally
D. Dilation of ipsilateral pupil
View Answer
A. Constriction of ipsilateral pupil to light ✅ Exp: Direct response = same eye.
15. Consensual light reflex is:
A. Constriction of contralateral pupil to light
B. Constriction of ipsilateral pupil
C. Both pupils dilate
D. No response
View Answer
A. Constriction of contralateral pupil to light ✅ Exp: Opposite eye constricts via bilateral innervation.
16. Relative afferent pupillary defect (RAPD) is best tested by:
A. Cover test
B. Swinging flashlight test
C. Maddox rod
D. Worth’s test
View Answer
B. Swinging flashlight test ✅ Exp: Detects asymmetric afferent defect.
17. In RAPD, affected eye shows:
A. Paradoxical dilation on light
B. Normal constriction
C. No change
D. Slow constriction
View Answer
A. Paradoxical dilation on light ✅ Exp: Swinging light causes dilation due to weaker afferent signal.
18. Marcus Gunn pupil indicates lesion in:
A. Optic nerve
B. Oculomotor nerve
C. Sympathetic pathway
D. Ciliary ganglion
View Answer
A. Optic nerve ✅ Exp: Afferent pathway defect (optic nerve, retina).
19. Argyll Robertson pupil is associated with:
A. Syphilis
B. Diabetes
C. Glaucoma
D. Optic neuritis
View Answer
A. Syphilis ✅ Exp: Light-near dissociation; classic in neurosyphilis.
20. Light-near dissociation is seen in:
A. Argyll Robertson pupil
B. Adie’s tonic pupil
C. Optic neuritis
D. Both A & B
View Answer
D. Both A & B ✅ Exp: AR pupil (syphilis) and Adie’s pupil show preserved near reflex but absent light reflex.
21. Dark adaptation involves regeneration of:
A. Opsin
B. Rhodopsin
C. Iodopsin
D. Retinol
View Answer
B. Rhodopsin ✅ Exp: Rod pigment regeneration allows night vision.
22. Primary vitamin involved in dark adaptation:
A. Vitamin A
B. Vitamin B1
C. Vitamin C
D. Vitamin D
View Answer
A. Vitamin A ✅ Exp: Retinol → 11-cis-retinal.
23. Time taken for full dark adaptation:
A. 5 min
B. 15–30 min
C. 60 min
D. 2 min
View Answer
B. 15–30 min ✅ Exp: Rod adaptation takes 20–30 minutes.
24. The Purkinje shift during dark adaptation refers to:
A. Shift of spectral sensitivity to shorter wavelengths
B. Shift to longer wavelengths
C. No change
D. Shift in visual field
View Answer
A. Shift of spectral sensitivity to shorter wavelengths ✅ Exp: Rods dominate, peak at 507 nm (blue-green).
25. Light adaptation occurs within:
A. Seconds
B. Minutes
C. Hours
D. Days
View Answer
A. Seconds ✅ Exp: Cones adapt quickly to bright light.
26. Adie’s tonic pupil results from lesion in:
A. Ciliary ganglion
B. Optic nerve
C. Oculomotor nucleus
D. Edinger-Westphal nucleus
View Answer
A. Ciliary ganglion ✅ Exp: Parasympathetic denervation of sphincter.
27. Pupil in Adie’s tonic pupil is:
A. Large, reacts poorly to light, better to near
B. Small, brisk light reflex
C. Large, brisk reflex
D. Mid-dilated, fixed
View Answer
A. Large, reacts poorly to light, better to near ✅ Exp: Classic light-near dissociation
28. Holmes-Adie pupil shows hypersensitivity to:
A. 0.125% pilocarpine
B. Atropine
C. Tropicamide
D. Cocaine
View Answer
A. 0.125% pilocarpine ✅ Exp: Denervated sphincter supersensitive to dilute pilocarpine.
29. Horner’s syndrome triad includes:
A. Miosis, ptosis, anhidrosis
B. Mydriasis, ptosis, sweating
C. Miosis, lid lag, proptosis
D. Ptosis, mydriasis, hyperhidrosis
View Answer
A. Miosis, ptosis, anhidrosis ✅ Exp: Sympathetic lesion → classic triad.
30. Cocaine test for Horner’s syndrome works by:
A. Blocking reuptake of norepinephrine
B. Blocking ACh
C. Blocking dopamine
D. Blocking serotonin
View Answer
A. Blocking reuptake of norepinephrine ✅ Exp: Normal pupil dilates; Horner’s pupil fails to dilate.
