This disorder arises from a weakness of the muscles in one or both eyes, leading to crossed or misaligned eyes, which may lead to disoriented or double vision. Since this disorder forms mostly in babies, early corrective steps are required. These include corrective eye lenses, surgery to straighten and realign the muscles, injected medication to relax the contracted muscles and eye patches or eye drops.
Are there different types of squint?
Yes, squints can be divided into different categories:
- By the direction of the squinting (turning) eye:
- An eye that turns inwards is called an esotropia.
- An eye that turns outwards is called an exotropia.
- An eye that turns upwards is called a hypertropia.
- An eye that turns downwards is called a hypotropia.
- Whether the squint is present all the time (constant), or comes and goes (intermittent).
- Whether the affected eye turns when the eyes are open and being used (manifest squint) or whether the eye turns only when it is covered or shut (latent squint), but looks fine when the eyes are open.
- Whether the severity (angle) of the squint is the same in all directions or not:
- A concomitant squint means that the angle (degree) of the squint is always the same in every direction that you look. That is, the two eyes move well, all the muscles are working, but the two eyes are always out of alignment by the same amount, no matter which way you look.
- An incomitant squint means that the angle of squint can vary. For example, when you look to the left, there may be no squint and the eyes are aligned. But when you look to the right, one eye may not move as far and the eyes are then not aligned.
- By age of onset. Most squints develop at some time in the first three years of life. Some develop in older children and adults. Squints that develop in children usually have different causes to those that develop in adults.
- By the cause:
- In many cases of childhood squint, the reason why a squint develops is not known.
- In some cases of childhood squint (and most cases of adult squint), the squint occurs because of a disorder of the eye, the eye muscles, the brain or the nerves.
Treatment typically involves the following:
- Treating amblyopia (visual loss) if this is present.
- Wearing glasses to correct any refractive error, if this is present.
- Surgery is often needed to correct the appearance of the squint itself, and may help to restore binocular vision in some cases.