Embarrassing Illnesses

The cause of a squint is not always known. Squints sometimes run in families and a baby can be born with the condition (congenital squint).

Squints are also sometimes the result of childhood illnesses or other sight-related problems, such as long-sightedness (hypermetropia).

Congenital squints

A child is either born with a squint or develops one during the first six months of life.

Sometimes other family members have a squint, which suggests it can be genetic.

In most cases of congenital squint, the eye turns inwards (congenital esotropia). It is also possible (although rarer) for the eye to turn outwards (congenital exotropia).

Refractive errors

Squints are sometimes caused by the eye's inability to focus the light that passes through the lens. This is known as a refractive error, and is also the cause of conditions such as short-sightedness (myopia), long-sightedness (hypermetropia) and astigmatism (where the cornea at the front of the eye is unevenly curved).

See Useful links for more information about these other conditions.

If a child has a refractive error, their eye may turn inwards as it attempts to focus. Squints caused by refractive errors usually develop in children who are two or older and tend to be most common in children who are long-sighted.

Other causes

Most squints are congenital or caused by refractive errors. Occasionally, squints can be the result of:

• childhood illnesses, such as viral infections like measles,
• some genetic conditions, such as Noonan syndrome, or
• a brain condition, such as hydrocephalus where there is too much cerebrospinal fluid (CSF) in the ventricles (cavities) of the brain.