California Optometry Licensing
Examination with Practice Questions And
Correct Answers (V
1. A patient with keratoconus is being fitted with a scleral lens. Which fitting
parameter is most critical to avoid midperipheral corneal touch and central vault?
A. Base curve radius
B. Lens diameter
C. Sagittal depth
D. Peripheral curve radius
Answer: C. Sagittal depth
Rationale: Sagittal depth determines the central vault and midperipheral clearance;
insufficient sagittal depth causes corneal touch, while excessive sagittal depth leads to
bubble formation. Base curve, diameter, and peripheral curves influence fit but are
secondary to sagittal depth in scleral lens fitting for keratoconus.
2. Which visual field defect is most characteristic of a lesion at the optic chiasm?
A. Homonymous hemianopia
B. Bitemporal hemianopia
C. Central scotoma
D. Arcuate scotoma
Answer: B. Bitemporal hemianopia
Rationale: Chiasmal lesions compress crossing nasal fibers, producing bitemporal
hemianopia. Homonymous hemianopia indicates retrochiasmal lesions, central scotoma
suggests optic neuropathy, and arcuate scotoma is typical of glaucoma.
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,3. During a cover test, a patient shows no movement when the cover is removed from
the right eye, but the left eye moves inward to fixate when uncovered. What is the
most likely diagnosis?
A. Right esotropia
B. Left exotropia
C. Right hypertropia
D. Left hypotropia
Answer: B. Left exotropia
Rationale: Inward movement of the left eye upon uncovering indicates it was diverged
(exotropic) and now must converge to fixate. The right eye shows no movement because it
is the fixating eye. This is consistent with left exotropia.
4. Which of the following best describes the mechanism of action of prostaglandin
analogs in lowering intraocular pressure?
A. Increase trabecular outflow
B. Decrease aqueous production
C. Increase uveoscleral outflow
D. Increase episcleral venous pressure
Answer: C. Increase uveoscleral outflow
Rationale: Prostaglandin analogs (e.g., latanoprost) primarily enhance uveoscleral outflow
by remodeling the extracellular matrix in the ciliary muscle. They do not significantly affect
trabecular outflow or aqueous production.
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,5. A patient with diabetes presents with sudden painless vision loss and a normal
fundus exam. Which test is most likely to reveal the cause?
A. Optical coherence tomography (OCT)
B. Fluorescein angiography (FA)
C. Visual evoked potential (VEP)
D. Electroretinography (ERG)
Answer: B. Fluorescein angiography (FA)
Rationale: In diabetic retinopathy, sudden vision loss with a normal fundus may indicate
vitreous hemorrhage or macular edema not visible on exam; FA can detect leakage or
nonperfusion. OCT may show edema but FA is more sensitive for vascular abnormalities.
6. Which of the following is a contraindication for the use of contact lenses?
A. Mild dry eye
B. Keratoconus
C. Active ocular infection
D. High myopia
Answer: C. Active ocular infection
Rationale: Active ocular infection (e.g., bacterial keratitis) is an absolute contraindication
for contact lens wear due to risk of exacerbation and corneal damage. Mild dry eye,
keratoconus, and high myopia can be managed with appropriate lens designs.
Page 3 of 66
, 7. A patient reports diplopia that worsens when looking to the right. Which cranial
nerve palsy is most likely?
A. CN III
B. CN IV
C. CN VI
D. CN VII
Answer: C. CN VI
Rationale: CN VI (abducens) palsy causes weakness of the lateral rectus, leading to
horizontal diplopia that worsens when looking toward the affected side. CN III affects
multiple muscles, CN IV causes vertical/torsional diplopia, and CN VII is facial nerve.
8. Which of the following best describes the purpose of the Farnsworth D-15 test?
A. Assess contrast sensitivity
B. Evaluate color vision deficiencies
C. Measure visual acuity
D. Detect glaucoma
Answer: B. Evaluate color vision deficiencies
Rationale: The Farnsworth D-15 is a color arrangement test used to screen for and classify
color vision defects, particularly red-green and blue-yellow deficiencies. It does not
measure acuity, contrast sensitivity, or glaucoma.
Page 4 of 66
Examination with Practice Questions And
Correct Answers (V
1. A patient with keratoconus is being fitted with a scleral lens. Which fitting
parameter is most critical to avoid midperipheral corneal touch and central vault?
A. Base curve radius
B. Lens diameter
C. Sagittal depth
D. Peripheral curve radius
Answer: C. Sagittal depth
Rationale: Sagittal depth determines the central vault and midperipheral clearance;
insufficient sagittal depth causes corneal touch, while excessive sagittal depth leads to
bubble formation. Base curve, diameter, and peripheral curves influence fit but are
secondary to sagittal depth in scleral lens fitting for keratoconus.
2. Which visual field defect is most characteristic of a lesion at the optic chiasm?
A. Homonymous hemianopia
B. Bitemporal hemianopia
C. Central scotoma
D. Arcuate scotoma
Answer: B. Bitemporal hemianopia
Rationale: Chiasmal lesions compress crossing nasal fibers, producing bitemporal
hemianopia. Homonymous hemianopia indicates retrochiasmal lesions, central scotoma
suggests optic neuropathy, and arcuate scotoma is typical of glaucoma.
Page 1 of 66
,3. During a cover test, a patient shows no movement when the cover is removed from
the right eye, but the left eye moves inward to fixate when uncovered. What is the
most likely diagnosis?
A. Right esotropia
B. Left exotropia
C. Right hypertropia
D. Left hypotropia
Answer: B. Left exotropia
Rationale: Inward movement of the left eye upon uncovering indicates it was diverged
(exotropic) and now must converge to fixate. The right eye shows no movement because it
is the fixating eye. This is consistent with left exotropia.
4. Which of the following best describes the mechanism of action of prostaglandin
analogs in lowering intraocular pressure?
A. Increase trabecular outflow
B. Decrease aqueous production
C. Increase uveoscleral outflow
D. Increase episcleral venous pressure
Answer: C. Increase uveoscleral outflow
Rationale: Prostaglandin analogs (e.g., latanoprost) primarily enhance uveoscleral outflow
by remodeling the extracellular matrix in the ciliary muscle. They do not significantly affect
trabecular outflow or aqueous production.
Page 2 of 66
,5. A patient with diabetes presents with sudden painless vision loss and a normal
fundus exam. Which test is most likely to reveal the cause?
A. Optical coherence tomography (OCT)
B. Fluorescein angiography (FA)
C. Visual evoked potential (VEP)
D. Electroretinography (ERG)
Answer: B. Fluorescein angiography (FA)
Rationale: In diabetic retinopathy, sudden vision loss with a normal fundus may indicate
vitreous hemorrhage or macular edema not visible on exam; FA can detect leakage or
nonperfusion. OCT may show edema but FA is more sensitive for vascular abnormalities.
6. Which of the following is a contraindication for the use of contact lenses?
A. Mild dry eye
B. Keratoconus
C. Active ocular infection
D. High myopia
Answer: C. Active ocular infection
Rationale: Active ocular infection (e.g., bacterial keratitis) is an absolute contraindication
for contact lens wear due to risk of exacerbation and corneal damage. Mild dry eye,
keratoconus, and high myopia can be managed with appropriate lens designs.
Page 3 of 66
, 7. A patient reports diplopia that worsens when looking to the right. Which cranial
nerve palsy is most likely?
A. CN III
B. CN IV
C. CN VI
D. CN VII
Answer: C. CN VI
Rationale: CN VI (abducens) palsy causes weakness of the lateral rectus, leading to
horizontal diplopia that worsens when looking toward the affected side. CN III affects
multiple muscles, CN IV causes vertical/torsional diplopia, and CN VII is facial nerve.
8. Which of the following best describes the purpose of the Farnsworth D-15 test?
A. Assess contrast sensitivity
B. Evaluate color vision deficiencies
C. Measure visual acuity
D. Detect glaucoma
Answer: B. Evaluate color vision deficiencies
Rationale: The Farnsworth D-15 is a color arrangement test used to screen for and classify
color vision defects, particularly red-green and blue-yellow deficiencies. It does not
measure acuity, contrast sensitivity, or glaucoma.
Page 4 of 66
