Page 144 - The Indian Optician Digital Edition May-June 2023

Cover test is required to find the type
of squint whether phoria or tropia. It is the
gold standard for the objective method
for determining the presence, type and
magnitude of ocular misalignment. It is of
two types: cover- uncover test and alternative
cover test. A master hand can be able to
perform this test in a proper way to get
accurate evaluation findings.

COVER TEST

 Eye moves toward the nose as ii is
uncovered - exo
 Eye moves temporally as it is
uncovered - eso
 Eye moves downward as it is
uncovered - hyper deviation of that eye

F. Neutralise movement with prism. Alternate
cover test is repeated as described in steps A – D
with prism in front of one eye. (The prism bar may
be held by the patient or the examiner). Increase
the amount of prisms until no movement is
observed as the eye is uncovered (or until the
motion reverses to the opposite direction).

PRISM SHOULD BE ADDED AS FOLLOWS:

OBSERVED MOTION PRISM ORIENTATION
Exo base in

Eso base out
Hyper base down
Hypo base up UN-COVER TEST

140 | THE INDIAN OPTICIAN | MAY-JUNE 2023 OPTOMETRY