Squints and Lazy Eyes

Amblyopia or ‘lazy eye’ is a condition where the vision in one or both eyes cannot be corrected to 20/20 vision even with glasses.

When vision develops normally, the brain receives information from each eye and ‘combines’ or ‘fuses’ this information into a single image. This process of forming a single clear image giving a 3D perception of the world is known as ‘fusion’.

Amblyopia occurs when the brain is unable to ‘fuse’ an equally clear image from each eye.

For example, if one of the eyes has turned so that one eye is looking in a different direction to the other eye, the brain will be receiving two different images.

One of these images will be you, if they are looking at you and the other image would be whatever the other eye is looking at, say a wall.

Rather than have an image of a wall superimposed on top of an image of your face, the brain will ‘turn off’ or ‘suppress’ the one eye so that eye does not see as well.

This is termed as ‘strabismic amblyopia’. It is also known as ‘squint’ in describing the eye that is turning.

Amblyopia can also occur where one of the eyes requires a much stronger spectacle lens to see clearly compared to the other eye. If a child is not given appropriate glasses at an early age the brain does not learn how to see properly out of the eye that requires the stronger lens.

This is termed as ‘anisometropic amblyopia’.

In both of these cases the brain learns to ignore or suppress the information from the one eye leading to reduced central vision in that eye. Note that the peripheral vision in that eye can still be good.

Most squints and lazy eyes in children are treated in eye hospitals by the NHS. In the case of lazy eyes treatment is by the use of glasses. Sometimes drops will be put into the eyes to give the strongest glasses possible. This is because the hospital wants to see if by putting drops in the eye to relax the eye muscles the eye will straighten.

Patients can also be ‘patched’ where the better seeing eye is covered with a patch in order to encourage the patient to use the other eye and so get it to work better.

In the case of squints or eye turns other treatment options include squint surgery and Botox injections.

Squint surgery is used to surgically alter the length of the eye muscles that move the eye so that the eye can be straightened. Botox injections work to weaken the strength of the eye muscles so that the eye does not turn as much.

Treatment for squints and amblyopia through the NHS usually stops at the age of seven as ophthalmology and orthoptics strongly believe that no improvement in vision can be made beyond this age.

Treatment for amblyopia and squint in adults is usually restricted to surgery and Botox injections.

A different approach in terms of vision training has shown however that it is possible to offer some improvement to squints and lazy eyes at almost any age. We have examples of patients who have benefited from intervention.

Every case is different and improvements with any individual patient are challenging to predict though age is not a limitation.

At the moment this service is not available to patients currently being treated by the eye hospital.

However, we are happy to offer an opinion once your treatment with the eye hospital has been completed and they have decided to discharge you.

Treatment strategies may include fitting you with contact lenses rather than glasses and bifocal or varifocal glasses rather than ordinary distance glasses.

Sectorial patching and vision training are other treatment options.