Practice 30 high-yield MCQs with answers and explanations Designed for NEET PG, NEXT, AIIMS, and MRCSEd Ophthalmology preparation, optometrist examination.

General Features of Eyeball

1. The eyeball is best described as:
A. Perfect sphere
B. Oblate spheroid
C. Ellipsoid
D. Sphere with uniform curvature

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B. Oblate spheroid ✅ Explanation: Eyeball is not a true sphere but an oblate spheroid.

2. The anteroposterior diameter of an adult eyeball is:
A. 22 mm
B. 23 mm
C. 24 mm
D. 25 mm.

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C. 24 mm ✅ Explanation: Adult AP diameter ≈ 24 mm.

3. The horizontal diameter of eyeball is:
A. 22.5 mm
B. 23.5 mm
C. 24 mm
D. 25 mm

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B. 23.5 mm ✅ Explanation: Horizontal = 23.5 mm.

4. The vertical diameter of eyeball is:
A. 22 mm
B. 23 mm
C. 23.5 mm
D. 24 mm

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B. 23 mm ✅ Explanation: Vertical = 23 mm.

5. The volume of adult eyeball is about:
A. 5 ml
B. 6.5 ml
C. 7.5 ml
D. 8 ml

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B. 6.5 ml ✅ Explanation: Eyeball volume ≈ 6.5 ml.

6. Average weight of adult eyeball:
A. 5 g
B. 6 g
C. 7 g
D. 8 g

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C. 7 g ✅ Explanation: Adult eyeball ≈ 7 g.

7. The anterior pole of eyeball refers to:
A. Corneal apex
B. Optic disc
C. Limbus
D. Macula

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A. Corneal apex ✅ Explanation: Central point of corneal curvature.

8. The posterior pole is:
A. Macula
B. Optic disc
C. Central point on posterior convexity
D. Fovea centralis

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C. Central point on posterior convexity ✅ Explanation: Posterior pole = central point on posterior surface.

9. Equator of eyeball lies:
A. At corneoscleral junction
B. Midway between anterior and posterior poles
C. Through optic nerve
D. At limbus

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B. Midway between anterior and posterior poles ✅ Explanation: Equator lies at mid-plane.

10. Circumference of adult eyeball:
A. 65 mm
B. 70 mm
C. 75 mm
D. 80 mm

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C. 75 mm ✅ Explanation: Adult circumference ≈ 75 mm.

Coats of the Eyeball

11. Fibrous coat of eyeball includes:
A. Iris + sclera
B. Cornea + sclera
C. Choroid + sclera
D. Retina + sclera

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B. Cornea + sclera ✅ Explanation: Fibrous coat = cornea (1/6) + sclera (5/6).

12. Junction of cornea and sclera:
A. Limbus
B. Ora serrata
C. Optic disc
D. Equator

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A. Limbus ✅ Explanation: Corneoscleral junction = limbus.

13. Vascular coat of eyeball is also called:
A. Uvea
B. Retina
C. Corneoscleral coat
D. Endothelium

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A. Uvea ✅ Explanation: Uveal tract = iris, ciliary body, choroid.

14. Nervous coat of eyeball is:
A. Sclera
B. Retina
C. Choroid
D. Iris

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B. Retina ✅ Explanation: Retina forms nervous coat.

15. Which layer is responsible for vision?
A. Sclera
B. Retina
C. Cornea
D. Lens

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B. Retina ✅ Explanation: Retina processes visual signals.

Segments & Chambers

16. The anterior segment includes:
A. Vitreous
B. Retina
C. Lens, cornea, iris, anterior & posterior chambers
D. Optic disc

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C. Lens, cornea, iris, anterior & posterior chambers ✅ Explanation: Anterior segment = lens + structures anterior to it.

17. Average depth of anterior chamber in adults:
A. 1.5 mm
B. 2.5 mm
C. 3.0 mm
D. 4.0 mm

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B. 2.5 mm ✅ Explanation: Depth ≈ 2.5 mm at centre.

18. Anterior chamber volume:
A. 0.15 ml
B. 0.25 ml
C. 0.35 ml
D. 0.5 ml

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B. 0.25 ml ✅ Explanation: Contains ≈ 0.25 ml aqueous humour.

19. Posterior chamber volume:
A. 0.02 ml
B. 0.04 ml
C. 0.06 ml
D. 0.1 ml

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C. 0.06 ml ✅ Explanation: Posterior chamber ≈ 0.06 ml aqueous humour.

20. Posterior segment contains:
A. Cornea + iris
B. Lens + aqueous humour
C. Vitreous + retina + choroid + optic disc
D. Sclera + conjunctiva

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C. Vitreous + retina + choroid + optic disc ✅ Explanation: Posterior segment = structures behind lens.

Cornea & Sclera

21. Transparency of cornea is due to:
A. Blood supply
B. Regular stromal arrangement
C. Thick stroma
D. Pigment cells

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B. Regular stromal arrangement ✅, Explanation: Transparency due to avascularity + uniform collagen lamellae.

22. Which part of fibrous coat is transparent?
A. Sclera
B. Cornea
C. Iris
D. Retina

B. Cornea Explanation: Cornea transmits light.

23. Sclera forms how much of fibrous coat?
A. 1/4
B. 1/2
C. 5/6
D. 3/4

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C. 5/6 ✅ Explanation: Posterior 5/6 of fibrous coat is sclera.

Lens, Iris & Ciliary Body Relations

24. Cornea forms how much of fibrous coat?
A. 1/2
B. 1/4
C. 1/6
D. 1/8

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C. 1/6 ✅ Explanation: Anterior 1/6 is cornea.

25. Lens is suspended from:
A. Iris
B. Retina
C. Ciliary body via zonules
D. Sclera

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C. Ciliary body via zonules ✅ Explanation: Zonular fibres hold lens.

26. The iris is part of:
A. Retina
B. Cornea
C. Uveal tract
D. Fibrous coat

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C. Uveal tract ✅ Explanation: Uveal coat has iris anteriorly.

27. Ciliary body lies between:
A. Iris & sclera
B. Iris & choroid
C. Cornea & iris
D. Retina & sclera

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B. Iris & choroid ✅ Explanation: Ciliary body is between iris & choroid.

28. Depth of anterior chamber is shallower in:
A. Myopia
B. Hypermetropia
C. Emmetropia
D. Presbyopia

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B. Hypermetropia ✅ Explanation: Hypermetropes → shallow chamber.

29. Depth of anterior chamber is deeper in:
A. Hypermetropia
B. Myopia
C. Presbyopia
D. Emmetropia

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B. Myopia ✅ Explanation: Myopes → deeper chamber.

30. Normal adult anterior chamber depth is:
A. 1 mm
B. 2.5 mm
C. 3.5 mm
D. 4 mm

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B. 2.5 mm ✅ Explanation: Depth ≈ 2.5 mm.