Certified Ophthalmic Assistant (COA)
Study Guide 2025/2026 – Complete Exam
Prep
How are systemic medications administered? - Answer-Orally, injection
(subcutaneously or intramuscularly) or intravenously
How should drops be properly instilled into a patient's eye? - Answer-Into the lower cul
de sac (lower fornix)
What does the term idiosyncrasy refer to with ophthalmic drugs? - Answer-A bizarre,
peculiar reaction to a drug that is not commonly seen, such as tremors, excitability or
even collapse
What is the name of the instrument used to neutralize lenses? - Answer-Lensometer
(Lensmeter)
When recording a prism in a spectacle prescription, what does the abbreviation BO
stand for? - Answer-Base out
What is determined by focusing the thin lines in a manual lensometer? - Answer-The
sphere of the spectacle prescription
What is the first step in performing lensometry? - Answer-Focus the eyepiece
When PRK is being performed, time remaining in the procedure should be announced
in increments of ______ - Answer-10 seconds
Name the organism that is most destructive to the eye. - Answer-Pseudomonas
Aeruginosa
What procedure using an Argon Laser is thought to destroy areas of ischemic retina? -
Answer-Panretinal photocoagulation or panretinal laser
What type of intraocular injection is made at the Pars plana site with a needle and
syringe of medication? - Answer-Intravitreal injection
,What are the parallel movements of the eyes from one gaze position to another -
Answer-Versions
What is the movement of one eye called - Answer-Duction
Versions and ductions are tested by using ________ to test the six pairs of _______
muscles. - Answer-Six Cardinal positions, yoke
What is the most popular injected anesthetic for minor procedures? - Answer-Lidocaine
When performing cover-uncover test, the eye under the cover moves when uncovered,
it is a ____, which is a ____ deviation. - Answer-Phoria, latent
Drainage of topical drops from the eye and their systemic absorption can be prevented
by ____ ____. - Answer-Punctal occlusion
What medications are used as topical anesthetics? - Answer-Proparacaine or tetracaine
What is the color of bottle caps of prostaglandins? - Answer-Teal
What are the classificaitons of the three large groups of anti-infective agents? - Answer-
Antibiotics, antivirals, and antifungals
True allergic reaction can involve what symptoms? - Answer-Itching, rash, difficulty
breathing, weak or rapid pulse
In terms of lens thickness, the greater the refractive index, the ____ the lens - Answer-
thinner
The distance from the center of the pupil of one eye to the center of the pupil of the
other eye is termed ____. - Answer-Interpupillary Distance
What is measured to obtain a monocular measurement of the IPD (interpupillary
distance) - Answer-The distance from the bridge of the nose to the center of a pupil.
Explain how to transpose a spherocylinder lens from plus to minus cylinder form, or
from minus to plus cylinder. - Answer-Algebraically add the sphere and cylinder powers,
retain the cylinder power but change the cylinder sign, and change the cylinder axis by
90 degrees.
Transpose: +2.00 -2.50 x 90
-0.50 + 2.50 x 180
,Which instrument measures the radius of curvature, or base curve, of a spectacle lens
surface in diopters? - Answer-Geneva lens clock or measure
What is the spherical equivalent of -2.00 +3.00 x 90 - Answer--0.50 sphere
The trifocal portion of a +2.00 reading add will be ____. - Answer-+1.00
What is the name of the test to determine the correct myopic correction using red/green
filter on the projector? - Answer-Duochrome test
What is another reference or starting point for refracting a patient who has a poor
retinoscopy reflex? - Answer-Keratometry
What normally determines the strength of an add power for near correction? - Answer-
The age of the patient
What type of refractometry is indicated for children with accommodative esotropia or
patients who have latent hyperopia? - Answer-Cycloplegic refractometry
what is the distance from the back surface of a lens to the front surface of the eye
called? - Answer-Vertex distance
Define refractometry. - Answer-The measurement of the refractive error of an eye
What is the name of the instrument that houses various lenses to determine the
refractive error of an eye? - Answer-Phoropter
What is an important factor when preparing a patient for refraction? - Answer-The
refractionist must explain to the patient to choose the lens that provides the clearest
vision
What is a common mistake made by a refractionist? - Answer-Moving or flipping the
lenses too quickly for the patient
What are three appropriate starting points for refracting a patient? - Answer-
Retinoscopy, autorefractometry, or patient's current spectacle prescription
In what order should refinement of a refraction be performed? - Answer-Sphere, axis,
then power of cylinder
What accessory phoropter lens is utilized to refine cylinder axis and power? - Answer-
Jackson Cross Cylinder
Name the 2 methods of refractometry. - Answer-Objective and Subjective
, In refractometry, the ____ method requires the patient to give answers to the examiner.
- Answer-Subjective
When is the spherical equivalent best used in a spectacle prescription? - Answer-If a
patient is an adult who has never worn glasses and requires a large astigmatic
correction.
Computer assisted corneal topography is instrumental in early diagnosis of ____. -
Answer-Keratoconus
Corneal topography uses ____ colors to denote steeper areas of the cornea and ____
colors to denote flatter areas of the cornea. - Answer-Warm (red, orange)
Cool (blue)
Today's computer assisted corneal topography systems are based on data obtained
from a reflected ____ ____ image. - Answer-Placido disc
____ does not appear on magnetic resonance imaging (MRI). - Answer-Bone
Conjunctivitis may be ____, ____, or ____. - Answer-Allergic
Viral
Bacterial
Sudden painless vision loss, which may continue to deteriorate over a few days, and
may not recover is known as ____ ____ ____. - Answer-Ischemic Optic Neuropathy
Forward displacement of the eye in its bony socket causing the eye to bulge forward is
termed ____. - Answer-Proptosis / exophthalmus
The cornea provides approximately ____ of the refractive power of the eye. - Answer-
2/3
If dust accumulates on the mirror of the slit lamp, the technician may clean it by using
what cleaning methods? - Answer-A lint-free cloth, a lens brush, or a blast of air.
Who should repair and maintain equipment such as a laser? - Answer-A qualified
service technician
A pupil diameter of less than ____ can produce a contraction of the visual field -
Answer-2 - 2.5 mm
Normal peripheral limits of the visual field are ____ degrees nasally, ____ degrees
superiorly, ____ degrees inferiorly, and ____ degrees temporally. - Answer-60
60
70
90
Study Guide 2025/2026 – Complete Exam
Prep
How are systemic medications administered? - Answer-Orally, injection
(subcutaneously or intramuscularly) or intravenously
How should drops be properly instilled into a patient's eye? - Answer-Into the lower cul
de sac (lower fornix)
What does the term idiosyncrasy refer to with ophthalmic drugs? - Answer-A bizarre,
peculiar reaction to a drug that is not commonly seen, such as tremors, excitability or
even collapse
What is the name of the instrument used to neutralize lenses? - Answer-Lensometer
(Lensmeter)
When recording a prism in a spectacle prescription, what does the abbreviation BO
stand for? - Answer-Base out
What is determined by focusing the thin lines in a manual lensometer? - Answer-The
sphere of the spectacle prescription
What is the first step in performing lensometry? - Answer-Focus the eyepiece
When PRK is being performed, time remaining in the procedure should be announced
in increments of ______ - Answer-10 seconds
Name the organism that is most destructive to the eye. - Answer-Pseudomonas
Aeruginosa
What procedure using an Argon Laser is thought to destroy areas of ischemic retina? -
Answer-Panretinal photocoagulation or panretinal laser
What type of intraocular injection is made at the Pars plana site with a needle and
syringe of medication? - Answer-Intravitreal injection
,What are the parallel movements of the eyes from one gaze position to another -
Answer-Versions
What is the movement of one eye called - Answer-Duction
Versions and ductions are tested by using ________ to test the six pairs of _______
muscles. - Answer-Six Cardinal positions, yoke
What is the most popular injected anesthetic for minor procedures? - Answer-Lidocaine
When performing cover-uncover test, the eye under the cover moves when uncovered,
it is a ____, which is a ____ deviation. - Answer-Phoria, latent
Drainage of topical drops from the eye and their systemic absorption can be prevented
by ____ ____. - Answer-Punctal occlusion
What medications are used as topical anesthetics? - Answer-Proparacaine or tetracaine
What is the color of bottle caps of prostaglandins? - Answer-Teal
What are the classificaitons of the three large groups of anti-infective agents? - Answer-
Antibiotics, antivirals, and antifungals
True allergic reaction can involve what symptoms? - Answer-Itching, rash, difficulty
breathing, weak or rapid pulse
In terms of lens thickness, the greater the refractive index, the ____ the lens - Answer-
thinner
The distance from the center of the pupil of one eye to the center of the pupil of the
other eye is termed ____. - Answer-Interpupillary Distance
What is measured to obtain a monocular measurement of the IPD (interpupillary
distance) - Answer-The distance from the bridge of the nose to the center of a pupil.
Explain how to transpose a spherocylinder lens from plus to minus cylinder form, or
from minus to plus cylinder. - Answer-Algebraically add the sphere and cylinder powers,
retain the cylinder power but change the cylinder sign, and change the cylinder axis by
90 degrees.
Transpose: +2.00 -2.50 x 90
-0.50 + 2.50 x 180
,Which instrument measures the radius of curvature, or base curve, of a spectacle lens
surface in diopters? - Answer-Geneva lens clock or measure
What is the spherical equivalent of -2.00 +3.00 x 90 - Answer--0.50 sphere
The trifocal portion of a +2.00 reading add will be ____. - Answer-+1.00
What is the name of the test to determine the correct myopic correction using red/green
filter on the projector? - Answer-Duochrome test
What is another reference or starting point for refracting a patient who has a poor
retinoscopy reflex? - Answer-Keratometry
What normally determines the strength of an add power for near correction? - Answer-
The age of the patient
What type of refractometry is indicated for children with accommodative esotropia or
patients who have latent hyperopia? - Answer-Cycloplegic refractometry
what is the distance from the back surface of a lens to the front surface of the eye
called? - Answer-Vertex distance
Define refractometry. - Answer-The measurement of the refractive error of an eye
What is the name of the instrument that houses various lenses to determine the
refractive error of an eye? - Answer-Phoropter
What is an important factor when preparing a patient for refraction? - Answer-The
refractionist must explain to the patient to choose the lens that provides the clearest
vision
What is a common mistake made by a refractionist? - Answer-Moving or flipping the
lenses too quickly for the patient
What are three appropriate starting points for refracting a patient? - Answer-
Retinoscopy, autorefractometry, or patient's current spectacle prescription
In what order should refinement of a refraction be performed? - Answer-Sphere, axis,
then power of cylinder
What accessory phoropter lens is utilized to refine cylinder axis and power? - Answer-
Jackson Cross Cylinder
Name the 2 methods of refractometry. - Answer-Objective and Subjective
, In refractometry, the ____ method requires the patient to give answers to the examiner.
- Answer-Subjective
When is the spherical equivalent best used in a spectacle prescription? - Answer-If a
patient is an adult who has never worn glasses and requires a large astigmatic
correction.
Computer assisted corneal topography is instrumental in early diagnosis of ____. -
Answer-Keratoconus
Corneal topography uses ____ colors to denote steeper areas of the cornea and ____
colors to denote flatter areas of the cornea. - Answer-Warm (red, orange)
Cool (blue)
Today's computer assisted corneal topography systems are based on data obtained
from a reflected ____ ____ image. - Answer-Placido disc
____ does not appear on magnetic resonance imaging (MRI). - Answer-Bone
Conjunctivitis may be ____, ____, or ____. - Answer-Allergic
Viral
Bacterial
Sudden painless vision loss, which may continue to deteriorate over a few days, and
may not recover is known as ____ ____ ____. - Answer-Ischemic Optic Neuropathy
Forward displacement of the eye in its bony socket causing the eye to bulge forward is
termed ____. - Answer-Proptosis / exophthalmus
The cornea provides approximately ____ of the refractive power of the eye. - Answer-
2/3
If dust accumulates on the mirror of the slit lamp, the technician may clean it by using
what cleaning methods? - Answer-A lint-free cloth, a lens brush, or a blast of air.
Who should repair and maintain equipment such as a laser? - Answer-A qualified
service technician
A pupil diameter of less than ____ can produce a contraction of the visual field -
Answer-2 - 2.5 mm
Normal peripheral limits of the visual field are ____ degrees nasally, ____ degrees
superiorly, ____ degrees inferiorly, and ____ degrees temporally. - Answer-60
60
70
90
