A lazy eye (amblyopia) is often diagnosed and treated by an orthoptist under the supervision of an ophthalmologist.

The younger the child is when a lazy eye is diagnosed, the more successful treatment is likely to be. If treatment is started after the age of eight, it is unlikely to be as successful.

The two main treatment options for a lazy eye are:

• treating or correcting any underlying eye problems
• encouraging the use of the affected eye so that vision can develop properly

Treating underlying eye problems

Glasses

Vision problems such as short- or long-sightedness can be corrected using glasses. These usually need to be worn constantly and are checked regularly.

Glasses may also help to straighten a squint, and in some cases can fix the lazy eye without the need for further treatment.

Your child may say that they can see better without their glasses. This is because their eyes have become used to working hard to focus, and they now find it hard to let the glasses focus for them. They will need plenty of encouragement to wear their glasses continuously.

An alternative to glasses are contact lenses, although these may only be suitable for older children.

Read more about treating short-sightedness and long-sightedness with corrective lenses.

Surgery

In children, most cataracts are removed to allow better development of vision in the affected eye.

Cataract surgery for children is carried out under general anaesthetic, and the procedure can sometimes take as little as 20 to 30 minutes.

Your child may be kept in hospital overnight to check their recovery process, and they may have to use eye drops afterwards.

Read more about the treatment of cataracts in children.

In some cases, surgery is used to improve the appearance of a squint. The operation will either strengthen or weaken the eye muscles of the lazy eye to change its position. This means that the lazy eye will appear to be better aligned with the good eye. The child's vision will not improve, but their eyes will appear straighter and it will help the eyes work better together.

Read more about treating squints.

A droopy eyelid (ptosis) can also be corrected using surgery.

Encouraging the use of the eye

A number of different treatments options can be used to encourage your child to use the affected eye. These are outlined below.

Using a patch

Using a patch is known as occlusion. It involves placing a patch with a sticky rim over the "good" eye so that the lazy eye is forced to work. It can be very effective in improving the sight in the lazy eye.

The length of time the child will need to wear the patch will depend on how old they are, how serious the problem is and how much they co-operate with wearing the patch.

The orthoptist and opthalmologist will determine how often follow-up checks are needed.

Patches are most effective before a child reaches seven or eight years of age. Most children will need to wear the patch for a few hours a day for several weeks. While the patch is on, the child should do close-up activities, such as colouring, reading or schoolwork. Patches can be worn with glasses.

Using a patch to treat a lazy eye can be a time-consuming process, and it can sometimes be an unpleasant experience for the child. It is important to explain to your child the reasons for using a patch and the importance of sticking with the treatment so that they are motivated to do it.

Eye drops

Atropine eye drops can be used to blur the vision in the good eye. They dilate (expand) the pupil of the good eye and blur near vision, which encourages the use of the lazy eye. Side effects that can occur after using eye drops include:

• eye irritation
• flushing (reddening) of the skin
• headaches

However, these side effects are usually infrequent and they rarely outweigh the benefits of using eye drops. 

Eye drops can be as effective as using a patch and often the choice of treatment is a matter of preference. So, children who don't like having drops in their eyes can wear a patch and vice versa.

Lack of compliance

In some cases, a lazy eye does not improve despite proper treatment being received. However, some poor results of the treatment of a lazy eye are because of a lack of compliance from either the parent or carer, or the child. It is very important that a suitable treatment is found that can be stuck to.

If you are having trouble with one kind of treatment, you should discuss an alternative with your orthoptist (specialist in childhood eye problems).

If surgery is recommended, you should be aware that it can take more than one operation to improve the appearance of a squint. Also, after surgery, glasses may still need to be worn, and if the lazy eye returns, a patch may still be necessary.

If surgery is recommended to improve the position of the eyes (for example, to treat a squint), more than one operation may be required and glasses may still need to be worn. 

Generally, surgery is offered after successful treatment for a lazy eye, but patches or drops (occlusion treatment) may still be required after surgery to treat a squint.