A squint is when your eyes don’t look in exactly the same direction. It is a condition that causes one of the eyes to turn inwards, outwards, up or down when the other eye is looking straight ahead.
What are the signs and symptoms of a squint?
The most obvious sign of a squint is when one of your eyes is not looking straight ahead. You may also look at things with one eye closed. This may be because you have double vision, which can be present in some types of squint.
What causes squints?
The causes of a squint vary from person to person, and in many cases, the cause is unknown. Some children are born with a squint – or it might develop within the first six months of age. Sometimes a squint can run in the family. It can happen because you have muscle or nerve problems in your eye.
Most children with a squint are otherwise healthy. However, in some cases, a squint is one feature of a more generalised genetic or brain condition. For example, a squint may develop in some children with cerebral palsy, hydrocephalus, brain injury, and various other conditions.
A common cause of childhood squint is ‘refractive error’ – a need for glasses to help the eyes to focus correctly. One example of this is when you are long sighted.
How is a squint normally diagnosed and treated?
The most common way a squint is detected is when family or friends notice that the two eyes do not appear to be working together.
It is important to diagnose a squint as early as possible as untreated squint can lead to a reduction in vision in the squinting eye – this is known as amblyopia.
If you have a suspected squint you will usually be referred to an orthoptist. An orthoptist is a health professional who is specially trained to assess and manage children with squint and amblyopia. If necessary, an orthoptist will refer you to an ophthalmologist (eye doctor) for further assessment and treatment.
Treatment of squint
- Glasses may be prescribed to help with the visual development of your eyes and in some types of squint they may also help improve the alignment of the eyes
- The main treatment for amblyopia is to restrict the use of the good eye. This then forces the affected eye to work. If this is done early enough in childhood, your vision will usually improve, often up to a near-normal level. In effect, the visual development of the affected eye catches up. The common way this is done is to put a patch over the good eye. This is called occlusion.
Note: some people think that eye-patching is a treatment to correct the appearance of a squint. It is not. Eye patching and other treatments for amblyopia aim to improve vision and do not correct the appearance of a squint.
- Surgery may be needed if none of the above treatments work or they’re unsuitable for you. The surgeon will move the muscles to a different position.
Looking forward
With amblyopia as a rule of thumb, the younger you’re treated, the better, and the faster any improvement will be. Then you should have a good chance of having near normal vision. If treatment starts when you’re eight or older then may get some improvement in your vision, but you probably will not achieve completely normal vision.
If you have a squint and have surgery, this usually works well to straighten your eyes, but this may not be perfect. Sometimes one or two more operations are needed.
For more help and information
If you would like to know more about squints/strabismus please ask your doctor.
Last reviewed by Great Ormond Street Hospital: 15 September 2006
