1
COA Study Guide Test-1 Questions &
Answers with Rationale Top Rated Latest
Version 2026
What should be used to clean the accessible lenses of a
phoropter?
Photographic lens cleaner and lens tissue
What size letters (optotypes) are typically used to calibrate
visual acuity projectors?
20/200
What is the name of the instrument used to neutralize
lenses?
Lensometer (Lensmeter)
When recording prism in a spectacle Rx, what does the
abbreviation BO stand for?
Base out
What is determined by focusing the thin lines in a manual
lensometer?
The sphere of the spectacle Rx is determined by the thin lines.
What is the first step in performing lensometry?
Focus the eyepiece.
If you cannot center the thick and thin lines in the
lensometer, the lens has _______.
Ground-in prism.
Each black ring seen in the lensometer eyepiece reticle
measures how much prism?
1 diopter for each ring
When performing lensometry, what is indicated if both thin
and wide lines are in focus at the same time?
The lens is spherical.
What is the technique used to measure the radius of
curvature of the anterior corneal surface?
A-Scan Keratometry Length Measurements
,2
Keratometry is performed with a device called a ______.
Keratometer or ophthalmometer
Give three examples in which a keratometry measurement
would be useful.
Contact lens fitting, refractive surgery, intra ocular lens
calculations, keratoconus
Keratometry is measured in _______.
Diopters
An unfocused eyepiece can lead to an error of _______.
1 diopter in the K reading
How many meridians are measured in keratometry?
2 meridians (usually 90 degrees apart)
The average K reading is _____.
43 to 44 diopters
Keratometry measures the _______ of the anterior curvature
of the cornea.
Central 3.3 mm
The diffusion of oxygen through a contact lens material is
referred to as _______.
DK value
True or false: The application and evaluation of diagnostic
lens on the eye is the best way to fit a contact lens.
True
Name the instrument used to determine the posterior surface
radius of curvature of the rigid contact lens?
Radiuscope and or Contacto Gauge
Name three reasons to dispense a therapeutic bandage
contact lens.
To protect cornea from eyelids and eyelashes, to promote corneal
healing, to provide comfort, to stop wound leaks, to improve
vision, or for drug delivery.
Name two measurements required to fit a contact lens.
Refraction and K-reading (keratometry)
Overwear of contact lenses may result in insufficient oxygen
to the cornea called _______.
, 3
Hypoxia Ophthalmia
What are Ethics?
Moral Principles and values that govern individual behavior
What must ophthalmic medical assistants abide by?
The laws of the state in which their employer practices and under
the service of a licensed ophthalmologist
Attempting to work independently of an ophthalmologist is
considered _______.
Practicing medicine without a license
What should an ophthalmic practice have in place to meet
legal compliance?
A compliance officer, policies and procedures
What is HIPAA?
Health Insurance Portability and Accountability Act
What does HIPAA protect?
The dissemination of specific patient information
What is coding?
The application of numerical designations for medical diagnosis,
procedures, and services
What is the assessment of the use of services by a practice
institution, clinic, or individual physician?
Utilization review
Complete the statement: "If it isn't documented, _____."
It didn't happen
What is ICD - 9 - CM?
International Classification of diseases, ninth revision, clinical
modification
What important process is documented when the physician
or physician delegate educates the patient on the risks,
benefits, and alternatives of a surgical procedure and asks
for the patient's understanding and participation in the
decision making process?
Informed consent
As an ophthalmic assistant, you will record your findings in
what legal document?
COA Study Guide Test-1 Questions &
Answers with Rationale Top Rated Latest
Version 2026
What should be used to clean the accessible lenses of a
phoropter?
Photographic lens cleaner and lens tissue
What size letters (optotypes) are typically used to calibrate
visual acuity projectors?
20/200
What is the name of the instrument used to neutralize
lenses?
Lensometer (Lensmeter)
When recording prism in a spectacle Rx, what does the
abbreviation BO stand for?
Base out
What is determined by focusing the thin lines in a manual
lensometer?
The sphere of the spectacle Rx is determined by the thin lines.
What is the first step in performing lensometry?
Focus the eyepiece.
If you cannot center the thick and thin lines in the
lensometer, the lens has _______.
Ground-in prism.
Each black ring seen in the lensometer eyepiece reticle
measures how much prism?
1 diopter for each ring
When performing lensometry, what is indicated if both thin
and wide lines are in focus at the same time?
The lens is spherical.
What is the technique used to measure the radius of
curvature of the anterior corneal surface?
A-Scan Keratometry Length Measurements
,2
Keratometry is performed with a device called a ______.
Keratometer or ophthalmometer
Give three examples in which a keratometry measurement
would be useful.
Contact lens fitting, refractive surgery, intra ocular lens
calculations, keratoconus
Keratometry is measured in _______.
Diopters
An unfocused eyepiece can lead to an error of _______.
1 diopter in the K reading
How many meridians are measured in keratometry?
2 meridians (usually 90 degrees apart)
The average K reading is _____.
43 to 44 diopters
Keratometry measures the _______ of the anterior curvature
of the cornea.
Central 3.3 mm
The diffusion of oxygen through a contact lens material is
referred to as _______.
DK value
True or false: The application and evaluation of diagnostic
lens on the eye is the best way to fit a contact lens.
True
Name the instrument used to determine the posterior surface
radius of curvature of the rigid contact lens?
Radiuscope and or Contacto Gauge
Name three reasons to dispense a therapeutic bandage
contact lens.
To protect cornea from eyelids and eyelashes, to promote corneal
healing, to provide comfort, to stop wound leaks, to improve
vision, or for drug delivery.
Name two measurements required to fit a contact lens.
Refraction and K-reading (keratometry)
Overwear of contact lenses may result in insufficient oxygen
to the cornea called _______.
, 3
Hypoxia Ophthalmia
What are Ethics?
Moral Principles and values that govern individual behavior
What must ophthalmic medical assistants abide by?
The laws of the state in which their employer practices and under
the service of a licensed ophthalmologist
Attempting to work independently of an ophthalmologist is
considered _______.
Practicing medicine without a license
What should an ophthalmic practice have in place to meet
legal compliance?
A compliance officer, policies and procedures
What is HIPAA?
Health Insurance Portability and Accountability Act
What does HIPAA protect?
The dissemination of specific patient information
What is coding?
The application of numerical designations for medical diagnosis,
procedures, and services
What is the assessment of the use of services by a practice
institution, clinic, or individual physician?
Utilization review
Complete the statement: "If it isn't documented, _____."
It didn't happen
What is ICD - 9 - CM?
International Classification of diseases, ninth revision, clinical
modification
What important process is documented when the physician
or physician delegate educates the patient on the risks,
benefits, and alternatives of a surgical procedure and asks
for the patient's understanding and participation in the
decision making process?
Informed consent
As an ophthalmic assistant, you will record your findings in
what legal document?
