Diplopia - Treating double vision

If you have double vision, your treatment will depend on whether you have double vision in one eye (monocular) or both eyes (binocular), and the underlying cause.

Underlying conditions may be treated separately. Read more about the causes of double vision.

Double vision in one eye

If you're diagnosed with monocular double vision, treatment will depend on the underlying condition causing the problem.

Astigmatism

If you have monocular double vision caused by astigmatism (an abnormally curved cornea), you may be prescribed corrective lenses, such as glasses or contact lenses. Most children over the age of 12 are able to wear contact lenses.

Corrective lenses compensate for the uneven curve of the cornea so the incoming light that passes through the corrective lens is properly focused on the retina.

Laser surgery is another possible option for treating astigmatism, but it's not usually available free of charge on the NHS.

Read more about treating astigmatism.

Cataracts

If you have monocular double vision caused by cataracts (clouding of the lens), you may need cataract surgery to remove them.

If you have cataracts in both eyes, you'll have them removed on separate occasions to give the first eye time to heal and allow your vision to return.

Cataract operations are common procedures, usually performed as day surgery, which means you should be able to go home shortly afterwards.

Read more about cataract surgery, including how it's carried out and your recovery.

Double vision in both eyes

Treatment for binocular double vision also depends on the underlying cause. Read more about the causes of double vision.

Possible treatment options include:

• wearing glasses
• doing special eye exercises 
• fixing prisms on your glasses
• wearing an eye patch over one eye
• wearing an opaque (not see-through) contact lens in one eye
• having botulinum toxin (Botox) injections into an eye muscle
• having surgery on your eye muscles

Sometimes children are able to ignore double vision because their brain deals with the problem by ignoring, or "suppressing", one of the two images.

Most squints in children (when the eyes are pointing at different angles) are treated successfully if the condition is detected and treated early. Read more about treating squints.

Prisms

A prism is a wedge-shaped piece of glass or plastic that bends the light that shines though it. Special prisms called Fresnel (pronounced "frennel") prisms can be attached to your glasses, and are an effective way of treating double vision.

Fresnel prisms are thin, see-through sheets of plastic. One side sticks to the lens of your glasses and the other side has special grooves in it that change the way the light enters your eye.

You may need to wear prisms for several months. The strength can be adjusted to suit your eyes. If the Fresnel prisms are successful, you can have glasses made with prisms built in.

Botulinum toxin

Botulinum toxin (Botox) injections are sometimes used to treat eye movement disorders, such as squints.

The botulinum toxin is injected into one of the muscles controlling the movement of your eye. It blocks the chemical messages sent from the nerves and causes the muscle to relax. This means the muscle can no longer move your eye, and the other muscles take over and straighten the eye.

After the injection, you may experience some temporary side effects, such as:

• a droopy eyelid (ptosis)
• overcorrecting the position of your eye so your eyes are not aligned properly – this can mean your eye "drifts" slightly, and appears as if one eye is looking up or in the opposite direction
• worse double vision

As the botulinum toxin wears off, you may be able to control the position of your eyes for a period of time. However, this timeframe can vary and further injections may be necessary.

Surgery on your eye muscles

If your double vision is caused by a squint, surgery on your eye muscles can correct the position of your eyes. Any decision to have surgery is made on the basis that the benefit offered by the surgery (usually to align your eyes) is bigger than any risks.

There are six muscles controlling the position of each eye. Each muscle can be weakened, strengthened or moved. Depending on your particular squint, surgery can be carried out on the eye muscles to change the position of your eyes and realign them.

The risks of squint surgery include:

• making any double vision worse
• having a poor result from the operation, which could mean you need further squint surgery – this is estimated to affect around 1 in 10 people who have squint surgery
• in rare cases, damaging the eye or your vision – this is estimated to affect 1 in 2,400 people who have squint surgery

Your eyecare team will discuss the risks and benefits with you.

Opaque intraocular lens

For some cases of double vision, a surgical procedure known as opaque intraocular lens (IOL) may be an option. However, this procedure is only recommended when other treatments have been unsuccessful.

An opaque intraocular lens can only be used to treat people with binocular double vision (both eyes). The procedure usually involves removing the lens of the eye and replacing it with an implant.

Although it's considered a safe procedure, there are risks associated with having an opaque intraocular lens fitted. These include:

• the intraocular lens breaking after it has been inserted
• damage to the natural lens of the eye (if it is not removed)
• inability to examine the back part of the eye (retina)
• reduced visual field

Before having an opaque intraocular lens implant, you should discuss the implications of the procedure with your eye specialist. The procedure is irreversible, and removing the implant would involve significant risk of damaging your eye and impairing your vision.