Comprehensive MCQs with answers and explanations on Extraocular Muscle Palsies, Ocular Motility Disorders, and Binocular Vision mcq— covering cranial nerve palsies (CN III, IV, VI), Hess chart, Park’s three-step test, amblyopia, fusion, angle kappa, Hirschberg test, and Worth’s four-dot test. Ideal for ophthalmology exam preparation, NEET PG, AIIMS, and USMLE. optometry and ophthalmology mcq
Extraocular Muscle Palsies & Testing
31. In 6th nerve palsy, the affected muscle is:
A. Superior oblique
B. Lateral rectus
C. Inferior rectus
D. Medial rectus
View Answer
B. Lateral rectus ✅ Exp: CN VI supplies lateral rectus → abduction deficit.
32. Which is the commonest ocular motor nerve palsy?
A. CN III (oculomotor)
B. CN IV
C. CN VI
D. CN II
View Answer
A. CN III (oculomotor) ✅ Exp: Oculomotor nerve palsy most frequent.
33. Oculomotor nerve palsy presents with:
A. Ptosis
B. Eye deviated “down and out”
C. Dilated pupil
D. All of the above
View Answer
D. All of the above ✅ Exp: Classic triad due to paralysis of most EOMs + levator + sphincter pupillae.
34. Superior oblique palsy causes:
A. Vertical diplopia
B. Horizontal diplopia
C. Central scotoma
D. Loss of stereopsis only
View Answer
A. Vertical diplopia ✅ Exp: SO palsy → vertical/torsional diplopia.
35. Diplopia worse in downgaze suggests:
A. Superior oblique palsy
B. Lateral rectus palsy
C. Medial rectus palsy
D. Superior rectus palsy
View Answer
A. Superior oblique palsy ✅ Exp: SO depresses in adduction → worse in downgaze.
36. Paralysis of which muscle causes inability to look medially?
A. Lateral rectus
B. Medial rectus
C. Superior rectus
D. Superior oblique
View Answer
B. Medial rectus ✅ Exp: MR paralysis prevents adduction.
37. Hess chart is used for:
A. Measuring ocular deviation in muscle palsy
B. Visual acuity
C. Color vision
D. Stereopsis
View Answer
A. Measuring ocular deviation in muscle palsy ✅ Exp: Maps ocular movements & diplopia fields.
38. Park’s three-step test helps diagnose:
A. Vertical muscle palsies
B. Lateral rectus palsy
C. Amblyopia
D. Myopia
View Answer
A. Vertical muscle palsies ✅ Exp: Differentiates SO/IR/SR palsies.
39. Most common cause of isolated 6th nerve palsy in adults:
A. Diabetes mellitus
B. Trauma
C. Tumor
D. Hypertension only
View Answer
A. Diabetes mellitus ✅ Exp: Microvascular ischemia (DM, HTN).
40. Which cranial nerve has the longest intracranial course?
A. Optic nerve
B. Trochlear nerve (CN IV)
C. Abducent nerve
D. Oculomotor nerve
View Answer
B. Trochlear nerve (CN IV) ✅ Exp: CN IV = longest & thinnest → prone to injury.
Binocular Vision Development & Disorders
41. Normal development of binocular vision occurs by age:
A. Birth
B. 3–6 months
C. 1 year
D. 2 years
View Answer
B. 3–6 months ✅ Exp: Fusion and stereopsis appear by 3–6 months.
42. Amblyopia occurs due to:
A. Suppression of one eye
B. Retinal degeneration
C. Cataract only
D. Glaucoma only
View Answer
A. Suppression of one eye ✅ Exp: Functional visual loss from suppression during development.
43. The most common cause of amblyopia:
A. Strabismus
B. Anisometropia
C. Stimulus deprivation
D. Congenital cataract
View Answer
A. Strabismus ✅ Exp: Strabismic amblyopia most frequent.
44. Which amblyopia is most resistant to treatment?
A. Strabismic
B. Deprivation (e.g., congenital cataract)
C. Anisometropic
D. Stimulus deprivation late onset
View Answer
B. Deprivation (e.g., congenital cataract) ✅ Exp: Early deprivation leads to irreversible loss.
45. Treatment of amblyopia includes:
A. Correcting refractive error
B. Occlusion therapy
C. Penalization
D. All of the above
View Answer
D. All of the above ✅ Exp: All are standard treatments.
46. Occlusion therapy in amblyopia means:
A. Covering the better eye
B. Covering the lazy eye
C. Covering both eyes
D. No covering
View Answer
A. Covering the better eye ✅ Exp: Forces use of amblyopic eye.
47. Penalization therapy uses:
A. Atropine in better eye
B. Atropine in amblyopic eye
C. Patching amblyopic eye
D. Spectacle occlusion
View Answer
A. Atropine in better eye ✅ Exp: Blurs good eye with atropine to encourage use of weak eye.
48. Anisometropic amblyopia occurs due to:
A. Unequal refractive error between eyes
B. Strabismus
C. Optic neuritis
D. Glaucoma
View Answer
A. Unequal refractive error between eyes ✅ Exp: Significant refractive difference causes suppression.
49. Fusion defects commonly result in:
A. Diplopia
B. Color blindness
C. Night blindness
D. Optic atrophy
View Answer
A. Diplopia ✅ Exp: Fusion failure → double vision.
50. Panum’s fusional area is:
A. Area around corresponding points allowing fusion
B. Area of suppression
C. Area of diplopia
D. Macula only
View Answer
A. Area around corresponding points allowing fusion ✅ Exp: Small disparity tolerated to maintain fusion.
Special Tests & Clinical Points
51. The angle between visual axis and optical axis of eye:
A. Kappa angle
B. Alpha angle
C. Gamma angle
D. Phi angle
View Answer
A. Kappa angle ✅ Exp: Angle kappa is between visual axis & pupillary axis.
52. Positive angle kappa produces:
A. Pseudoexotropia
B. Pseudoesotropia
C. Diplopia
D. Suppression
View Answer
A. Pseudoexotropia ✅ Exp: Corneal light reflex displaced nasally → appears exotropic.
53. Negative angle kappa produces:
A. Pseudoesotropia
B. Pseudoexotropia
C. Diplopia
D. Stereopsis
View Answer
A. Pseudoesotropia ✅ Exp: Corneal reflex displaced temporally → appears esotropic.
54. Hirschberg test is used for:
A. Ocular alignment
B. Visual acuity
C. Color vision
D. Stereopsis
View Answer
A. Ocular alignment ✅ Exp: Uses corneal light reflex to estimate squint.
55. Normal Hirschberg reflex is displaced:
A. Centrally
B. Slightly nasal to pupil center
C. Slightly temporal
D. Absent
View Answer
B. Slightly nasal to pupil center ✅ Exp: Normally ~0.5 mm nasal.
56. Krimsky test uses:
A. Prism to neutralize corneal light reflex deviation
B. Maddox rod
C. Polarized glasses
D. Synoptophore
View Answer
A. Prism to neutralize corneal light reflex deviation ✅ Exp: Prism placed until reflex is centered.
57. Diplopia charting helps in:
A. Localizing paralyzed muscle
B. Measuring visual acuity
C. Detecting color vision defect
D. Measuring convergence
View Answer
A. Localizing paralyzed muscle ✅ Exp: Maps diplopia in different gazes.
58. Worth’s four-dot test result in suppression:
A. Patient sees 2 or 3 dots only
B. Patient sees 4 dots
C. Patient sees 5 dots
D. Patient sees none
View Answer
A. Patient sees 2 or 3 dots only ✅ Exp: Suppression → missing dots.
59. In fusion, the brain combines images from:
A. Non-corresponding retinal points
B. Corresponding retinal points
C. Suppressed retinal points
D. Only one eye
View Answer
B. Corresponding retinal points ✅ Exp: Corresponding points fuse into single perception.
60. Diplopia can be physiological when:
A. Images fall outside Panum’s fusional area
B. There is strabismus
C. Suppression occurs
D. Fusion is intact
View Answer
A. Images fall outside Panum’s fusional area ✅ Exp: Normal phenomenon when disparity > fusional limit.
