CERTIFIED OPHTHALMIC ASSISTANT
(COA) ACTUAL TEST 1 QUESTIONS AND
ANSWERS
1. Which of the following describes the correct transposition of the prescription +2.25 -1.75 x
085?
A. +0.50 -1.75 x 175
B. +0.50 +1.75 x 175
C. +4.00 +1.75 x 175
D. -0.50 +1.75 x 085
Answer: B
Conceptual Explanation: To transpose: add the sphere and cylinder algebraically (+2.25 +
-1.75 = +0.50), change the sign of the cylinder to plus (+1.75), and change the axis by 90
degrees (085 + 90 = 175).
2. Which corneal layer contains the ‘pump’ mechanism that maintains corneal
deturgescence?
A. Stroma
,B. Bowman’s membrane
C. Endothelium
D. Epithelium
Answer: C
Conceptual Explanation: The endothelium is a single layer of hexagonal cells that pumps
fluid out of the stroma to keep the cornea clear and dehydrated.
3. A patient with a ‘dendritic’ corneal ulcer most likely has which condition?
A. Acanthamoeba keratitis
B. Herpes simplex keratitis
C. Fungal keratitis
D. Bacterial ulcer
Answer: B
Conceptual Explanation: A classic dendritic (branch-like) lesion staining with fluorescein
is the hallmark of Herpes Simplex Virus epithelial keratitis.
4. Which extraocular muscle is primarily responsible for incyclotorsion, abduction, and
depression?
A. Superior Rectus
B. Superior Oblique
, C. Inferior Rectus
D. Inferior Oblique
Answer: B
Conceptual Explanation: The Superior Oblique muscle’s primary action is incyclotorsion,
and its secondary actions are depression and abduction.
5. What is the primary purpose of the ‘Jackson Cross Cylinder’ (JCC) during refraction?
A. To determine the spherical endpoint
B. To measure the near add
C. To refine cylinder axis and power
D. To detect binocular imbalance
Answer: C
Conceptual Explanation: The JCC is used to refine the axis and the power of the astigmatic
correction after an initial estimate is found.
6. Which pharmacological agent is a Miotic used in the treatment of glaucoma?
A. Cyclopentolate
B. Atropine
C. Timolol
D. Pilocarpine
(COA) ACTUAL TEST 1 QUESTIONS AND
ANSWERS
1. Which of the following describes the correct transposition of the prescription +2.25 -1.75 x
085?
A. +0.50 -1.75 x 175
B. +0.50 +1.75 x 175
C. +4.00 +1.75 x 175
D. -0.50 +1.75 x 085
Answer: B
Conceptual Explanation: To transpose: add the sphere and cylinder algebraically (+2.25 +
-1.75 = +0.50), change the sign of the cylinder to plus (+1.75), and change the axis by 90
degrees (085 + 90 = 175).
2. Which corneal layer contains the ‘pump’ mechanism that maintains corneal
deturgescence?
A. Stroma
,B. Bowman’s membrane
C. Endothelium
D. Epithelium
Answer: C
Conceptual Explanation: The endothelium is a single layer of hexagonal cells that pumps
fluid out of the stroma to keep the cornea clear and dehydrated.
3. A patient with a ‘dendritic’ corneal ulcer most likely has which condition?
A. Acanthamoeba keratitis
B. Herpes simplex keratitis
C. Fungal keratitis
D. Bacterial ulcer
Answer: B
Conceptual Explanation: A classic dendritic (branch-like) lesion staining with fluorescein
is the hallmark of Herpes Simplex Virus epithelial keratitis.
4. Which extraocular muscle is primarily responsible for incyclotorsion, abduction, and
depression?
A. Superior Rectus
B. Superior Oblique
, C. Inferior Rectus
D. Inferior Oblique
Answer: B
Conceptual Explanation: The Superior Oblique muscle’s primary action is incyclotorsion,
and its secondary actions are depression and abduction.
5. What is the primary purpose of the ‘Jackson Cross Cylinder’ (JCC) during refraction?
A. To determine the spherical endpoint
B. To measure the near add
C. To refine cylinder axis and power
D. To detect binocular imbalance
Answer: C
Conceptual Explanation: The JCC is used to refine the axis and the power of the astigmatic
correction after an initial estimate is found.
6. Which pharmacological agent is a Miotic used in the treatment of glaucoma?
A. Cyclopentolate
B. Atropine
C. Timolol
D. Pilocarpine
