Why do some people have a squint?

          A squint is a physical defect in which both eyes do not point in the same direction. This is also called strabismus or heterotropia – a disorder of the eye in which the alignment of the two ocular axes is not parallel.

          A person with this defect may have an inward squint (one eye may be directed towards the other eye), an upward or a downward squint. The squint is called ‘comitant’ if the deviation remains constant no matter in what direction the gaze is directed. It is called ‘noncomitant’ if the degree of misalignment varies with the direction of the gaze.

          Long-sightedness in children often causes an inward squint. On the other hand short-sightedness may produce an upward squint. If one or more of these muscles are paralyzed, the noncomitant squint occurs. 

          A squint is most often the result of some abnormality in the nervous controls. Acquired squints are usually due to nerve or muscle disease and cause double vision. In fact, the movement of the eye balls depends upon the action of six muscles – four of which are straight and two slanting. If the nerves of these eye muscles have developed some defect, the eye can develop a squint.

         With the progress in medical sciences now it has become possible to treat this defect. But it must be done at an early stage by wearing special glasses. These have a dark glass to cover the good eye to stop it from being used. This prevents the bad eye from becoming worse.

         Squint can also be treated by some orthoptic exercise which helps to strengthen the eye muscles. In some cases, an operation is necessary to strengthen a weak eye muscle or to weaken an extra strong one. The good eye is covered for some period before the correctional surgery. This is to enable the patient to use the previously unused eye and build up its vision.

          An interesting observation about squint-eyed people is that it is often difficult to judge the direction in which they look.