Squint

Abstract

The word “squint” refers to a failure of the visual axes to meet at the point of regard. For normal vision each eye must be focused on and lined up with the object of regard. The fact that we have two eyes positioned some 60 mm apart means that we can accumulate considerably more data about our environment than would be possible with one eye alone. This can best be exemplified by considering what happens when one eye is suddenly lost as the result of injury or disease. Apart from the obvious loss of visual field which necessitates turning the head to the blind side, the patient experiences impaired distance judgement. The skilled worker notices a deterioration in the ability to perform fine tasks and the elderly notice that they pour tea into the saucer rather than the cup. In time, depth perception may improve and the patient adapts to the defect to some extent; children may adapt to one eyed vision in a remarkable way.