Certified Ophthalmic Assistant| 189
Questions| WITH COMPLETE SOLUTIONS
Course
COA
✅ 1. Which structure controls the amount of light entering the eye?
A. Cornea
B. Lens
C. Iris
D. Retina
Answer: C – Iris
Explanation:
The iris contains muscles that control pupil size, regulating how much light enters the eye. The
cornea and lens focus light, but do not control its entry.
✅ 2. What is the correct Snellen visual acuity notation for a patient who reads
the 20/40 line at 20 feet?
A. 40/20
B. 20/40
C. 40/20 with correction
D. 20/20
Answer: B – 20/40
Explanation:
This means the patient can see at 20 feet what a person with normal vision can see at 40 feet. It
indicates reduced distance visual acuity.
✅ 3. Which instrument measures intraocular pressure (IOP)?
A. Tonometer
B. Retinoscope
C. Lensometer
D. Keratometer
Answer: A – Tonometer
Explanation:
A tonometer (e.g., Goldmann or non-contact “air puff”) is used to measure the pressure inside
the eye, essential in glaucoma detection.
,✅ 4. Which test is used to assess a patient’s peripheral vision?
A. Pachymetry
B. Perimetry
C. Keratometry
D. Tonometry
Answer: B – Perimetry
Explanation:
Visual field testing (perimetry) measures central and peripheral vision. It's vital in
glaucoma, retinal disease, and neurological conditions.
✅ 5. What is the primary purpose of using cycloplegic eye drops in refraction?
A. Dilate the pupil permanently
B. Paralyze the ciliary muscle
C. Treat eye infections
D. Anesthetize the cornea
Answer: B – Paralyze the ciliary muscle
Explanation:
Cycloplegic agents (e.g., cyclopentolate) temporarily paralyze accommodation, ensuring
accurate refractive measurements, especially in children.
✅ 6. Which part of the eye focuses light onto the retina for clear vision?
A. Sclera
B. Vitreous
C. Lens
D. Choroid
Answer: C – Lens
Explanation:
The lens fine-tunes focus by changing shape (accommodation). It works with the cornea to
direct light onto the retina’s macula.
✅ 7. Which color cap is used for a mydriatic drop?
,A. Red
B. Blue
C. Green
D. Yellow
Answer: A – Red
Explanation:
Red caps indicate mydriatics (e.g., tropicamide) — used to dilate the pupil for examination of
the posterior segment.
✅ 8. Which condition causes clouding of the natural lens?
A. Glaucoma
B. Cataract
C. Retinopathy
D. Macular degeneration
Answer: B – Cataract
Explanation:
A cataract is an opacification of the lens, resulting in blurred or dim vision, glare sensitivity,
and reduced contrast.
✅ 9. What is the correct step if a patient experiences severe pain and vision loss
after dilation?
A. Apply artificial tears
B. Document and continue exam
C. Refer immediately to the ophthalmologist
D. Advise rest
Answer: C – Refer immediately to the ophthalmologist
Explanation:
These are signs of acute angle-closure glaucoma, a medical emergency after dilation in
susceptible patients. Immediate referral is critical.
✅ 10. What is the purpose of using fluorescein dye in the eye?
A. To stain bacteria
B. To view blood vessels
, C. To detect corneal abrasions or defects
D. To paralyze eye muscles
Answer: C – To detect corneal abrasions or defects
Explanation:
Fluorescein dye highlights epithelial defects under cobalt blue light, revealing abrasions,
ulcers, or foreign bodies on the cornea.
✅ 11. Which of the following refractive errors is caused by an irregularly shaped cornea?
A. Myopia
B. Hyperopia
C. Astigmatism
D. Presbyopia
Answer: C – Astigmatism
Explanation:
Astigmatism results from an asymmetrical corneal curvature, causing blurred or distorted
vision at all distances.
✅ 12. Which structure drains aqueous humor from the anterior chamber?
A. Canal of Schlemm
B. Macula
C. Vitreous body
D. Fovea centralis
Answer: A – Canal of Schlemm
Explanation:
The Canal of Schlemm allows aqueous fluid to drain, helping maintain intraocular pressure.
Blockage can cause glaucoma.
✅ 13. What is the normal range for intraocular pressure (IOP)?
A. 0–10 mmHg
B. 10–21 mmHg
C. 20–35 mmHg
D. 25–40 mmHg
Answer: B – 10–21 mmHg
Explanation:
Questions| WITH COMPLETE SOLUTIONS
Course
COA
✅ 1. Which structure controls the amount of light entering the eye?
A. Cornea
B. Lens
C. Iris
D. Retina
Answer: C – Iris
Explanation:
The iris contains muscles that control pupil size, regulating how much light enters the eye. The
cornea and lens focus light, but do not control its entry.
✅ 2. What is the correct Snellen visual acuity notation for a patient who reads
the 20/40 line at 20 feet?
A. 40/20
B. 20/40
C. 40/20 with correction
D. 20/20
Answer: B – 20/40
Explanation:
This means the patient can see at 20 feet what a person with normal vision can see at 40 feet. It
indicates reduced distance visual acuity.
✅ 3. Which instrument measures intraocular pressure (IOP)?
A. Tonometer
B. Retinoscope
C. Lensometer
D. Keratometer
Answer: A – Tonometer
Explanation:
A tonometer (e.g., Goldmann or non-contact “air puff”) is used to measure the pressure inside
the eye, essential in glaucoma detection.
,✅ 4. Which test is used to assess a patient’s peripheral vision?
A. Pachymetry
B. Perimetry
C. Keratometry
D. Tonometry
Answer: B – Perimetry
Explanation:
Visual field testing (perimetry) measures central and peripheral vision. It's vital in
glaucoma, retinal disease, and neurological conditions.
✅ 5. What is the primary purpose of using cycloplegic eye drops in refraction?
A. Dilate the pupil permanently
B. Paralyze the ciliary muscle
C. Treat eye infections
D. Anesthetize the cornea
Answer: B – Paralyze the ciliary muscle
Explanation:
Cycloplegic agents (e.g., cyclopentolate) temporarily paralyze accommodation, ensuring
accurate refractive measurements, especially in children.
✅ 6. Which part of the eye focuses light onto the retina for clear vision?
A. Sclera
B. Vitreous
C. Lens
D. Choroid
Answer: C – Lens
Explanation:
The lens fine-tunes focus by changing shape (accommodation). It works with the cornea to
direct light onto the retina’s macula.
✅ 7. Which color cap is used for a mydriatic drop?
,A. Red
B. Blue
C. Green
D. Yellow
Answer: A – Red
Explanation:
Red caps indicate mydriatics (e.g., tropicamide) — used to dilate the pupil for examination of
the posterior segment.
✅ 8. Which condition causes clouding of the natural lens?
A. Glaucoma
B. Cataract
C. Retinopathy
D. Macular degeneration
Answer: B – Cataract
Explanation:
A cataract is an opacification of the lens, resulting in blurred or dim vision, glare sensitivity,
and reduced contrast.
✅ 9. What is the correct step if a patient experiences severe pain and vision loss
after dilation?
A. Apply artificial tears
B. Document and continue exam
C. Refer immediately to the ophthalmologist
D. Advise rest
Answer: C – Refer immediately to the ophthalmologist
Explanation:
These are signs of acute angle-closure glaucoma, a medical emergency after dilation in
susceptible patients. Immediate referral is critical.
✅ 10. What is the purpose of using fluorescein dye in the eye?
A. To stain bacteria
B. To view blood vessels
, C. To detect corneal abrasions or defects
D. To paralyze eye muscles
Answer: C – To detect corneal abrasions or defects
Explanation:
Fluorescein dye highlights epithelial defects under cobalt blue light, revealing abrasions,
ulcers, or foreign bodies on the cornea.
✅ 11. Which of the following refractive errors is caused by an irregularly shaped cornea?
A. Myopia
B. Hyperopia
C. Astigmatism
D. Presbyopia
Answer: C – Astigmatism
Explanation:
Astigmatism results from an asymmetrical corneal curvature, causing blurred or distorted
vision at all distances.
✅ 12. Which structure drains aqueous humor from the anterior chamber?
A. Canal of Schlemm
B. Macula
C. Vitreous body
D. Fovea centralis
Answer: A – Canal of Schlemm
Explanation:
The Canal of Schlemm allows aqueous fluid to drain, helping maintain intraocular pressure.
Blockage can cause glaucoma.
✅ 13. What is the normal range for intraocular pressure (IOP)?
A. 0–10 mmHg
B. 10–21 mmHg
C. 20–35 mmHg
D. 25–40 mmHg
Answer: B – 10–21 mmHg
Explanation:
