Squint

In a squint (strabismus), the eyes point in different directions: one may turn in, out, up or down, all the time or only at times.

• In children, it is often linked to long sight, short sight or astigmatism, and can run in families. Less often it has other causes, which is why every childhood squint should be examined.
• In adults, a new squint can follow diabetes, thyroid eye disease, myasthenia gravis, a stroke, a head injury or previous eye surgery. It often causes double vision.
• In children, the brain can learn to ignore the turned eye, leading to a lazy eye (amblyopia). Treatment works best when started early, ideally before about seven or eight years of age.

See a doctor if a child has a constant squint, if a baby over three months old has a squint that comes and goes, or if an adult develops a new squint or double vision.

• Glasses, which correct the focusing problem and can reduce or straighten some squints.
• Patching or eye drops to treat a lazy eye. This can take months.
• Prism glasses for mild double vision, and botulinum toxin injections, whose effect lasts a few months.
• Surgery on the eye muscles, when other treatment is not enough.

• The muscles on the outside of the eye are moved or tightened and held with dissolvable stitches. The eye is never taken out.
• Usually done under general anaesthetic as a day case. Children always have a general anaesthetic.
• In some adults, adjustable stitches allow the final position to be fine-tuned after waking, using numbing drops.
• Surgery does not change the vision itself or the need for glasses.

• Soreness usually lasts a few days. Redness can take up to three months to fade.
• Adults usually take one to two weeks off work; children usually return to school after about a week.
• Avoid swimming for about four weeks and contact sports for about six weeks.

Every operation carries some risk. Your doctor will go through the risks that apply to you before you decide.

• The eyes may end up slightly over- or under-corrected, or the squint may return later. Further surgery is sometimes needed.
• Double vision, which is usually temporary.
• Infection, cysts or scarring on the surface of the eye.
• Serious damage to the eye or vision is very rare.