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OPHTHALMIC ASSISTANT (COA) FINAL
EXAM PREP TESTBANK |600+ QS&AS
WITH 100% VERIFIED
ANSWERS|A+GRADE
Q1. Which layer of the eye is responsible for absorbing light
and preventing scatter?
a) Sclera
b) Retina
c) Choroid
d) Cornea
Correct Answer: c) Choroid
Rationale: The choroid is the vascular layer between the retina and
sclera. Its melanin absorbs stray light, reducing scatter and
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improving visual acuity. The sclera is the outer fibrous coat; retina
is neural tissue.
Q2. The clear, avascular structure that provides two-thirds of the
eye's refractive power is the:
a) Lens
b) Cornea
c) Aqueous humor
d) Vitreous humor
Correct Answer: b) Cornea
*Rationale: The cornea contributes approximately 43 diopters
(about 2/3 of total refractive power). The lens provides the
remaining 1/3 and accommodates. The aqueous and vitreous
have minimal refractive effect.*
Q3. Which cranial nerve innervates the lateral rectus muscle?
a) Cranial nerve III (oculomotor)
b) Cranial nerve IV (trochlear)
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c) Cranial nerve VI (abducens)
d) Cranial nerve II (optic)
Correct Answer: c) Cranial nerve VI (abducens)
Rationale: Abducens nerve (CN VI) innervates the lateral rectus,
which abducts the eye. CN III innervates all other extraocular
muscles except superior oblique (CN IV).
Q4. The fovea centralis is located in the center of the macula
and is responsible for:
a) Peripheral vision
b) Highest visual acuity and color vision
c) Night vision
d) Aqueous production
Correct Answer: b) Highest visual acuity and color vision
Rationale: The fovea contains only cones (no rods) and is
avascular, allowing light to reach photoreceptors directly. It
provides sharp, detailed central vision and color discrimination.
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Q5. The optic disc is also known as the:
a) Macula
b) Fovea
c) Blind spot
d) Ora serrata
Correct Answer: c) Blind spot
Rationale: The optic disc has no photoreceptors, creating a
physiological blind spot. It is the entry point of the optic nerve and
central retinal vessels.
Q6. Aqueous humor is produced by the:
a) Ciliary body (ciliary processes)
b) Trabecular meshwork
c) Schlemm's canal
d) Choroid
Correct Answer: a) Ciliary body (ciliary processes)
Rationale: The ciliary processes produce aqueous humor via active
OPHTHALMIC ASSISTANT (COA) FINAL
EXAM PREP TESTBANK |600+ QS&AS
WITH 100% VERIFIED
ANSWERS|A+GRADE
Q1. Which layer of the eye is responsible for absorbing light
and preventing scatter?
a) Sclera
b) Retina
c) Choroid
d) Cornea
Correct Answer: c) Choroid
Rationale: The choroid is the vascular layer between the retina and
sclera. Its melanin absorbs stray light, reducing scatter and
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improving visual acuity. The sclera is the outer fibrous coat; retina
is neural tissue.
Q2. The clear, avascular structure that provides two-thirds of the
eye's refractive power is the:
a) Lens
b) Cornea
c) Aqueous humor
d) Vitreous humor
Correct Answer: b) Cornea
*Rationale: The cornea contributes approximately 43 diopters
(about 2/3 of total refractive power). The lens provides the
remaining 1/3 and accommodates. The aqueous and vitreous
have minimal refractive effect.*
Q3. Which cranial nerve innervates the lateral rectus muscle?
a) Cranial nerve III (oculomotor)
b) Cranial nerve IV (trochlear)
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c) Cranial nerve VI (abducens)
d) Cranial nerve II (optic)
Correct Answer: c) Cranial nerve VI (abducens)
Rationale: Abducens nerve (CN VI) innervates the lateral rectus,
which abducts the eye. CN III innervates all other extraocular
muscles except superior oblique (CN IV).
Q4. The fovea centralis is located in the center of the macula
and is responsible for:
a) Peripheral vision
b) Highest visual acuity and color vision
c) Night vision
d) Aqueous production
Correct Answer: b) Highest visual acuity and color vision
Rationale: The fovea contains only cones (no rods) and is
avascular, allowing light to reach photoreceptors directly. It
provides sharp, detailed central vision and color discrimination.
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Q5. The optic disc is also known as the:
a) Macula
b) Fovea
c) Blind spot
d) Ora serrata
Correct Answer: c) Blind spot
Rationale: The optic disc has no photoreceptors, creating a
physiological blind spot. It is the entry point of the optic nerve and
central retinal vessels.
Q6. Aqueous humor is produced by the:
a) Ciliary body (ciliary processes)
b) Trabecular meshwork
c) Schlemm's canal
d) Choroid
Correct Answer: a) Ciliary body (ciliary processes)
Rationale: The ciliary processes produce aqueous humor via active
