Squint Treatment

The two eyes are aimed by six small muscles each, working in matched pairs so that both point at the same thing at the same moment. A squint is the alignment failing, so one eye looks somewhere other than where you are looking.

The balance is upset in several ways. An uncorrected focusing error is a common one in children: an eye that has to work hard to focus at near turns inwards as it does so. Poor vision in one eye from any cause lets that eye drift. A weak or palsied nerve, an overactive thyroid, an injury to the orbit and childhood development of the alignment system itself account for most of the rest.

Age changes what the squint means. A young child's brain suppresses the picture from the deviating eye to avoid confusion, and an eye that is suppressed through the years when vision is still developing never reaches normal sharpness. An adult brain cannot suppress, so a squint appearing in adult life causes double vision and is investigated for its cause before anything is done about the alignment.

The assessment is longer than most eye visits and usually takes an hour or more. Vision is measured in each eye separately, which in a small child is done with pictures, matching shapes or by watching how they object to one eye being covered.

The central part is the cover test. Your doctor or orthoptist covers and uncovers each eye while you look at a target, first far away and then close, and watches which eye moves and how far. That measures the size of the deviation and whether it is present all the time or only sometimes, and the measurements are repeated at different distances and in different directions of gaze because a squint is rarely the same size in all of them.

Drops are put in to relax the focusing muscle completely before the spectacle power is measured, since an uncorrected focusing error is a cause of squint and not merely a coincidence. The back of the eye is examined in every case, because an eye that has turned because it cannot see needs the reason found.

Glasses, where they are the answer, straighten the eye within days of being worn consistently, and the improvement lasts only as long as they are worn. Patching the stronger eye to bring on the weaker one is measured in months, with the hours per day set at review and reduced as the vision comes up.

Surgery on the eye muscles is a day case. The eye is red and gritty for two to three weeks and looks worse before it looks better, drops run for about four weeks, and most people are back at work or school within a week. Swimming waits three to four weeks. There is no cut on the skin and no visible scar.

The alignment settles over six to eight weeks, and your surgeon judges the result at that point and not on the first day. A second procedure is needed in a minority, more often where the squint was large or long-standing, and this is discussed with you beforehand.