Master the eye anatomy mcq of the orbit and extraocular muscles with these 40 high-yield MCQs designed for NEET PG, INI-CET, AIIMS, and FMGE aspirants, ophthalmic officers, DHS exams, DMER exams. Learn key topics like orbital walls, extraocular muscle actions, nerve supply, and clinical correlations. Perfect for quick revision and ophthalmology exam preparation — only on MCQ Zone, your trusted source for Ophthalmology MCQs.

Orbit – General Anatomy

1. Shape of the orbit is:
A. Cone
B. Quadrilateral pyramid
C. Sphere
D. Ellipsoid

View Answer

B. Quadrilateral pyramid ✅ Exp: Orbit resembles a 4-sided pyramid with apex posteriorly.

2. Average orbital volume in adults:
A. 25 ml
B. 30 ml
C. 35 ml
D. 40 ml

View Answer

B. 30 ml ✅ Exp: Orbital cavity volume ≈ 30 ml.

3. Volume occupied by eyeball within orbit:
A. One-third
B. One-half
C. Two-thirds
D. Three-fourths

View Answer

A. One-third ✅ Exp: Eyeball ~7 ml, orbit ~30 ml.

4. Roof of orbit is formed mainly by:
A. Frontal bone
B. Sphenoid greater wing
C. Maxilla
D. Zygomatic

View Answer

A. Frontal bone ✅ Exp: Orbital roof = frontal bone + lesser sphenoid.

5. Floor of orbit formed mainly by:
A. Maxilla
B. Frontal bone
C. Ethmoid
D. Lacrimal

View Answer

A. Maxilla ✅ Exp: Orbital floor = maxilla + zygomatic + palatine.

Orbital Walls

6. Medial wall of orbit includes:
A. Maxilla
B. Lacrimal, ethmoid, sphenoid
C. Zygomatic
D. Frontal

View Answer

B. Lacrimal, ethmoid, sphenoid ✅ Exp: Medial wall very thin (lamina papyracea).

7. Strongest orbital wall:
A. Medial
B. Lateral
C. Roof
D. Floor

View Answer

B. Lateral ✅ Exp: Lateral wall thick and strong.

8. Weakest orbital wall:
A. Floor
B. Roof
C. Lateral
D. Medial

View Answer

A. Floor ✅ Exp: Floor thin → blow-out fracture.

9. Apex of orbit contains:
A. Optic canal
B. Lacrimal gland
C. Supraorbital notch
D. Nasolacrimal duct

View Answer

A. Optic canal ✅ Exp: Optic nerve and ophthalmic artery pass through canal.

10. Orbital margin formed by:
A. Maxilla, frontal, zygomatic
B. Ethmoid, sphenoid, lacrimal
C. Nasal, palatine, temporal
D. Only sphenoid

View Answer

A. Maxilla, frontal, zygomatic ✅ Exp: Orbital rim formed by frontal, zygomatic, maxilla.

Extraocular Muscles – Basics

11. Total extraocular muscles:
A. 4
B. 6
C. 7
D. 8

View Answer

B. 6 ✅ Exp: 4 recti + 2 obliques.

12. Recti muscles arise from:
A. Sphenoid lesser wing
B. Common tendinous ring (annulus of Zinn)
C. Orbital rim
D. Lacrimal fossa

View Answer

B. Common tendinous ring (annulus of Zinn) ✅ Exp: Annulus of Zinn surrounds optic canal.

13. Superior oblique arises from:
A. Orbital roof (sphenoid)
B. Annulus of Zinn
C. Maxilla
D. Frontal bone

View Answer

A. Orbital roof (sphenoid) ✅ Exp: Arises from sphenoid, passes through trochlea.

14. Inferior oblique arises from:
A. Orbital floor (maxilla)
B. Annulus of Zinn
C. Lacrimal bone
D. Sphenoid

View Answer

A. Orbital floor (maxilla) ✅ Exp: Origin from anterior orbital floor.

15. Levator palpebrae superioris arises from:
A. Annulus of Zinn
B. Lesser wing of sphenoid
C. Orbital roof
D. Zygomatic

View Answer

B. Lesser wing of sphenoid ✅ Exp: LPS arises near optic canal.

Actions of Recti Muscles

16. Primary action of medial rectus:
A. Abduction
B. Adduction
C. Elevation
D. Depression

View Answer

B. Adduction ✅ Exp: MR → adduction.

17. Primary action of lateral rectus:
A. Adduction
B. Abduction
C. Elevation
D. Depression

View Answer

B. Abduction ✅ Exp: LR → abduction.

18. Primary action of superior rectus:
A. Elevation
B. Depression
C. Intorsion
D. Abduction

View Answer

A. Elevation ✅ Exp: SR elevates eye.

19. Secondary actions of superior rectus include:
A. Adduction + intorsion
B. Abduction + extorsion
C. Depression + abduction
D. Adduction only

View Answer

A. Adduction + intorsion ✅ Exp: SR = elevation + adduction + intorsion.

20. Primary action of inferior rectus:
A. Depression
B. Elevation
C. Intorsion
D. Adduction

View Answer

A. Depression ✅ Exp: IR depresses eye.

Actions of Oblique Muscles

21. Primary action of superior oblique:
A. Intorsion
B. Extorsion
C. Elevation
D. Depression

View Answer

A. Intorsion ✅ Exp: SO intorts the eye.

22. Secondary actions of superior oblique:
A. Abduction + depression
B. Adduction + elevation
C. Intorsion + elevation
D. Abduction + elevation

View Answer

A. Abduction + depression ✅ Exp: SO = intorsion + depression + abduction.

23. Primary action of inferior oblique:
A. Extorsion
B. Intorsion
C. Depression
D. Elevation

View Answer

A. Extorsion ✅ Exp: IO extorts the eye.

24. Secondary actions of inferior oblique:
A. Elevation + abduction
B. Depression + adduction
C. Intorsion + abduction
D. Depression only

View Answer

A. Elevation + abduction ✅ Exp: IO = extorsion + elevation + abduction.

25. Only muscle arising from anterior orbit:
A. Superior rectus
B. Inferior oblique
C. Medial rectus
D. Levator palpebrae

View Answer

B. Inferior oblique ✅ Exp: IO arises from anterior orbital floor.

Nerve Supply of Muscles

26. Lateral rectus supplied by:
A. Oculomotor
B. Abducens
C. Trochlear
D. Trigeminal

View Answer

B. Abducens ✅ Exp: LR → VI nerve.

27. Superior oblique supplied by:
A. Oculomotor
B. Trochlear
C. Abducens
D. Trigeminal

View Answer

B. Trochlear ✅ Exp: SO → IV nerve.

28. All other extraocular muscles supplied by:
A. Trochlear
B. Abducens
C. Oculomotor
D. Trigeminal

View Answer

C. Oculomotor ✅ Exp: Oculomotor → MR, SR, IR, IO, LPS.

29. Mnemonic “LR6 SO4, rest 3” indicates:
A. LR → CN VI, SO → CN IV, rest → CN III
B. LR → CN IV, SO → CN VI
C. LR → CN III, SO → CN VI
D. LR → CN V, SO → CN IV

View Answer

A. LR → CN VI, SO → CN IV, rest → CN III ✅ Exp: Helps recall innervation.

30. Levator palpebrae superioris innervation:
A. Abducens
B. Trochlear
C. Oculomotor
D. Trigeminal

View Answer

C. Oculomotor ✅ Exp: Supplied by superior division of CN III.

31. Paralysis of lateral rectus causes:
A. Medial squint (esotropia)
B. Lateral squint
C. Hypertropia
D. Hypotropia

View Answer

A. Medial squint (esotropia) ✅ Exp: Eye pulled medially.

32. Paralysis of superior oblique causes:
A. Vertical diplopia
B. Horizontal diplopia
C. Loss of abduction
D. Ptosis

View Answer

A. Vertical diplopia ✅ Exp: SO palsy → vertical diplopia.

33. Trochlear nerve palsy leads to:
A. Inability to intort
B. Inability to abduct
C. Inability to adduct
D. Inability to elevate

View Answer

A. Inability to intort ✅ Exp: SO palsy → intorsion loss.

34. Abducens nerve palsy leads to:
A. Medial deviation of eye
B. Lateral deviation
C. Vertical deviation
D. Ptosis

View Answer

A. Medial deviation of eye ✅ Exp: LR palsy → esotropia.

35. Oculomotor palsy leads to all EXCEPT:
A. Ptosis
B. Dilated pupil
C. Abduction of eye
D. Loss of elevation

View Answer

C. Abduction of eye ✅ Exp: CN III palsy leaves LR & SO intact → eye abducted & depressed.

Extraocular Movements

36. In primary position, all recti pull eye towards:
A. Posterior pole
B. Anterior pole
C. Lateral side
D. Medial side

View Answer

A. Posterior pole ✅ Exp: Recti contract to pull eye backward.

37. Yoke muscles are:
A. Same eye synergists
B. Contralateral synergists
C. Antagonists
D. Ipsilateral agonists

View Answer

B. Contralateral synergists ✅ Exp: Yoke muscles coordinate binocular movements.

38. Sherrington’s law relates to:
A. Reciprocal innervation of agonist/antagonist
B. Yoke muscles
C. Hering’s law
D. Accommodation

View Answer

A. Reciprocal innervation of agonist/antagonist ✅ Exp: One contracts, antagonist relaxes.

39. Hering’s law relates to:
A. Equal innervation of yoke muscles
B. Reciprocal innervation
C. Retinal correspondence
D. Accommodation

View Answer

A. Equal innervation of yoke muscles ✅ Exp: Both eyes receive equal innervation.

40. Bielschowsky head tilt test is used in diagnosis of:
A. Superior oblique palsy
B. Lateral rectus palsy
C. Oculomotor palsy
D. Ptosis

View Answer

A. Superior oblique palsy ✅ Exp: Head tilt exaggerates SO weakness.

You have now explored the foundation of orbital and extraocular muscle anatomy from their origins and actions to nerve supply. These 40 eye anatomy mcq are design to sharpen your clinical understanding and exam, helping you answer with accuracy in NEET PG, AIIMS, and other like DHS Exam, DMER exams, Ophthalmic officer exams and Optometrist medical exams.

Your journey through ophthalmology doesn’t stop here explore the next chapter on the Visual Pathway MCQs and take your preparation to the next level.