An abnormal condition in which one or the other eye diverges from the direction in
which the gaze is directed; also called "squint." In strabismus a tendency
exists for one eye to become the "master eye," and when the
person looks at an object, it is fixed by the master eye
while the other is seen to be directed in a slightly different direction. Squints may thus be
divergent if the
squinting eye looks away from the line of the master eye ("walleye"), or
convergent if it
looks towards the line of the master eye ("cross-eye").
Squints may be divided also into the
concomitant squints (commonly seen in childhood), in
which an imbalance exists in the strengths of the paired muscles that move the eyeball, and the rarer
paralytic squints, in which there is a complete or partial
paralysis of one or more muscles in the
affected eye.
The
appearance of a squint may lead the person to seek medical advice;
double vision may occur,
especially in paralytic squint.
Squint in young children is an important condition,
since the brain suppresses the image seen by the squinting eye; if
correction of the squint is delayed the eye may become functionally blind (amblyopia). In such circumstances the child will never
develop binocular vision.
Treatment of concomitant squint is by correcting any
casual refractive error with glasses, patching the normal eye to force the use of squinting eye and reverse amblyopia, and, if necessary, correcting residual
deviation by surgical adjustment of the eye muscle balance. Treatment must be
started early and, in such cases, excellent results are usually obtained.