A squint is a condition where your eyes look in different directions. One eye turns inwards, outwards, upwards or downwards while the other eye looks forwards. The medical name for a squint is strabismus.
The misalignment of the eyes can be caused by a problem with the eye muscles or by an uncorrected vision problem, such as short-sightedness or long-sightedness.
Read more about the causes of squint.
When to see a doctor
Squints are common and affect about 1 in 20 children. They usually develop before a child is five years of age, but they can appear later.
Up to around three months of age, many babies occasionally squint as their vision develops. This is normal and nothing to worry about.
If your child still has a squint after this age, you should visit your GP.
It is very important that a squint is picked up and treated as early as possible to avoid vision problems developing. If a squint is identified when a child is young, there is a good chance that it will be successfully treated.
Read more about the symptoms of squint.
How does a squint affect vision?
In young children, a squint can cause:
If your child has a squint, their eyes are no longer working together and they may see two images (double vision) instead of one. To avoid double vision, your child’s brain ignores the signals from the eye with the squint and only recognises images from the normal eye. As the squinting eye is not being used, it eventually becomes ‘lazy’.
In older children, a squint may cause double vision but not result in a lazy eye. This is because their vision has fully developed and their brain is unable to ignore signals from the eye with the squint.
If the vision in the eye that squints is poor, your child may have to wear a patch over their other eye to encourage the vision to develop.
Read more about how squints are treated.
Can adults get a squint?
Occasionally, squints that have been corrected during childhood reappear in adulthood. Squints that affect adults may cause double vision because the brain has been trained to collect images from both eyes.
You should visit your GP as soon as possible if you develop a new squint. They may refer you to an ophthalmologist (eye care specialist) who will carry out an examination to identify the cause.
Squints may cause a cosmetic problem in adults if the condition was not treated when they were young. In such cases, the appearance of a squint can lead to low self-esteem.
Types of squint
There are four different types of squint depending on the direction in which the eye turns. They are:
- esotropia - where the eye turns inwards
- exotropia - where the eye turns outwards
- hypertropia - where the eye turns upwards
- hypotropia - where the eye turns downwards
Hypertropia and hypotropia are less common than esotropia and exotropia.
Squints can also be:
- apparent at all times (constant), or
- only apparent at certain times (intermittent).
The cause, severity and direction of a squint will vary from person to person.
