NBEO – NATIONAL BOARD OF EXAMINERS IN OPTOMETRY
100 COMPLETE QUESTIONS AND ANSWERS | CONTENT WELL
ORGANIZED 2026/2027 LATEST UPDATE | 100 % RATED AND
VERIFIED SOLUTIONS | GET AN A+ (NEW VERSION!!!)
Aligned with NBEO Part I / Part II academic & clinical science scope, exam-style
difficulty
Correct answers are BOLD.
Explanations are in italics.
1. Which cranial nerve is responsible for pupillary constriction?
A. Optic nerve
B. Trochlear nerve
C. Abducens nerve
D. Oculomotor nerve
Parasympathetic fibers traveling with the oculomotor nerve control pupillary
constriction.
2. The refractive index of the cornea is approximately:
A. 1.00
B. 1.33
C. 1.376
D. 1.42
The cornea’s refractive index is about 1.376, contributing most of the eye’s
refractive power.
,3. Which retinal cells are primarily responsible for night vision?
A. Cones
B. Bipolar cells
C. Ganglion cells
D. Rods
Rods are highly sensitive to light and function best in low illumination.
4. The Purkinje shift refers to:
A. Change in pupil size with age
B. Shift of focus during accommodation
C. Shift in peak spectral sensitivity in low light
D. Shift in visual field with eye movement
Under scotopic conditions, peak sensitivity shifts toward shorter wavelengths.
5. The primary neurotransmitter released by photoreceptors is:
A. Dopamine
B. Acetylcholine
C. Glutamate
D. GABA
Photoreceptors continuously release glutamate, decreasing release in response to
light.
6. Which layer of the cornea regenerates most rapidly?
A. Bowman’s membrane
B. Stroma
C. Descemet’s membrane
D. Epithelium
, The corneal epithelium regenerates quickly after injury.
7. The normal intraocular pressure range is approximately:
A. 5–10 mmHg
B. 10–21 mmHg
C. 20–30 mmHg
D. 25–35 mmHg
Normal IOP typically ranges from 10 to 21 mmHg.
8. A relative afferent pupillary defect is best detected using:
A. Hirschberg test
B. Cover test
C. Swinging flashlight test
D. Maddox rod
The swinging flashlight test reveals asymmetry in afferent pupillary input.
9. Which structure is primarily responsible for aqueous humor production?
A. Iris
B. Trabecular meshwork
C. Ciliary body
D. Lens
The ciliary processes of the ciliary body secrete aqueous humor.
10. The visual pathway synapses in the lateral geniculate nucleus before
reaching:
100 COMPLETE QUESTIONS AND ANSWERS | CONTENT WELL
ORGANIZED 2026/2027 LATEST UPDATE | 100 % RATED AND
VERIFIED SOLUTIONS | GET AN A+ (NEW VERSION!!!)
Aligned with NBEO Part I / Part II academic & clinical science scope, exam-style
difficulty
Correct answers are BOLD.
Explanations are in italics.
1. Which cranial nerve is responsible for pupillary constriction?
A. Optic nerve
B. Trochlear nerve
C. Abducens nerve
D. Oculomotor nerve
Parasympathetic fibers traveling with the oculomotor nerve control pupillary
constriction.
2. The refractive index of the cornea is approximately:
A. 1.00
B. 1.33
C. 1.376
D. 1.42
The cornea’s refractive index is about 1.376, contributing most of the eye’s
refractive power.
,3. Which retinal cells are primarily responsible for night vision?
A. Cones
B. Bipolar cells
C. Ganglion cells
D. Rods
Rods are highly sensitive to light and function best in low illumination.
4. The Purkinje shift refers to:
A. Change in pupil size with age
B. Shift of focus during accommodation
C. Shift in peak spectral sensitivity in low light
D. Shift in visual field with eye movement
Under scotopic conditions, peak sensitivity shifts toward shorter wavelengths.
5. The primary neurotransmitter released by photoreceptors is:
A. Dopamine
B. Acetylcholine
C. Glutamate
D. GABA
Photoreceptors continuously release glutamate, decreasing release in response to
light.
6. Which layer of the cornea regenerates most rapidly?
A. Bowman’s membrane
B. Stroma
C. Descemet’s membrane
D. Epithelium
, The corneal epithelium regenerates quickly after injury.
7. The normal intraocular pressure range is approximately:
A. 5–10 mmHg
B. 10–21 mmHg
C. 20–30 mmHg
D. 25–35 mmHg
Normal IOP typically ranges from 10 to 21 mmHg.
8. A relative afferent pupillary defect is best detected using:
A. Hirschberg test
B. Cover test
C. Swinging flashlight test
D. Maddox rod
The swinging flashlight test reveals asymmetry in afferent pupillary input.
9. Which structure is primarily responsible for aqueous humor production?
A. Iris
B. Trabecular meshwork
C. Ciliary body
D. Lens
The ciliary processes of the ciliary body secrete aqueous humor.
10. The visual pathway synapses in the lateral geniculate nucleus before
reaching:
