Cover Test Flashcards
A cover test is used to determine:
- presence of a deviation (phoria or tropia)
- laterality/which eye (unilateral or alternating)
- frequency of the deviation (constant or intermittent)
- direction of the phoria or tropia
- magnitude (size) of the deviation
What is orthophoria?
The perfect alignment in the absence of a stimulus for fixation
Define Heterophoria/phoria
The tendency for the eyes to deviate when fusion is blocked
A small ___ is common in most people; overcome by fusion
phoria
A “posture” slightly inward is _____
esophoria
A “posture” slightly outward is ____
exophoria
When motor fusion is no longer enough to overcome a phoria, it is called a _________ phoria.
decompensating
A decompensating phoria could result in
discomfort or diplopia
-double VA may occur
Hetertropia/Tropia is a _____ deviation
manifest
_______ is when the visual axes of both eyes do not intersect at fixation.
Eye is NOT aligned properly
Heterotropia/Tropia
Heterotropia/Tropia leads to
diplopia or suppression of the deviated eye
A tropia could occur due to some of the following reasons:
- Ansiometropia (difference in refractive errors between the two eyes)
- Abnormality of the extraocular muscles or strabismus
- Eye disease
Cover-Uncover Test (Unilateral Cover Test): Helps to differentiate:
- presence of a deviation (phoria/tropia)
- laterality/which eye (unilateral or alternating)
- frequency of the deviation (constant/intermittent)
The cover-uncover test is done _____
first!
Alternating cover test determines the:
- direction of the phoria/tropia
- magnitude (size) of the deviation
Both Cover-Uncover (Unilateral Cover Test) and Alternating Cover Tests are performed at
distance AND near