If you have double vision, your treatment will depend on whether you have double vision in one or both eyes and the underlying cause. Monocular double vision is double vision in one eye. Binocular double vision is double vision that occurs when both eyes fail to work together properly.
An underlying condition that is causing your double vision may be treated separately. Read more about the causes of double vision.
Double vision in one eye
If you are diagnosed with monocular double vision, the type of treatment you receive will depend on the underlying condition that is causing the problem.
If you have monocular double vision that is caused by astigmatism (an abnormally curved cornea), you may be prescribed corrective lenses, such as glasses or contact lenses. Most children who are over 12 years of age are able to wear contact lenses.
Corrective lenses work by compensating for the uneven curve of the cornea so that 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 is not usually available free of charge on the NHS.
Read more about treating astigmatism.
If you have monocular double vision that is caused by cataracts (clouding of the lens), you may need to have cataract surgery to remove them. If you have cataracts in both eyes, you will have them removed on separate occasions to give the first eye time to heal and to allow your vision to return.
Cataract operations are common procedures and keyhole surgery is often used. The procedure is usually performed as day surgery, which means that you should be able to go home shortly afterwards. After the operation, you will need someone to look after you for the first 24 hours.
Read more about cataract surgery, including how it is carried out and your recovery.
Double vision in both eyes
Treatment for binocular double vision, as with monocular double vision, depends on the underlying cause. 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 injections into an eye muscle
- having surgery on your eye muscles
Sometimes, children are able to ignore double vision because their brain is able to deal with the problem by ignoring, or 'suppressing', one of the two images.
For most children with a squint (when the eyes are pointing at different angles), the outlook is very good provided the condition is detected and treated early. Read more about treating squints.
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.
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. Fresnel prisms can be very effective at treating double vision.
You may need to wear the Fresnel prisms for several months. The strength of the Fresnel prisms can be adjusted to suit your eyes. If the Fresnel prisms are successful, you can have glasses made with prisms built in.
Botulinum toxin injections are sometimes used to treat eye movement disorders, such as squints. Botulinum toxin is a poison, but in very small doses it is used to treat a range of different health conditions.
The botulinum toxin is injected into one of the muscles that controls the movement of your eye. It blocks the chemical messages that are 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 that your eyes are not aligned properly, which can mean your eye 'drifts' slightly and appears as if one eye is looking up or in the opposite direction
Surgery on your eye muscles
If you have a squint that is causing double vision, you can have surgery on your eye muscles to 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 of the surgery.
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
- damaging the eye or your vision
- having a poor result from the operation that could mean you need further squint surgery
Your eye care 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 treatment methods have been unsuccessful.
An opaque intraocular lens can only be used to treat people who have double vision in both eyes, not in one eye. The procedure usually involves removing the lens of the eye, either under local anaesthetic or general anaesthetic, and replacing it with an implant.
Although it is considered to be a safe procedure, there are also some risks that are 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)
Therefore, before having an opaque intraocular lens implant, you should discuss the implications of the procedure with your ophthalmologist (eye specialist). The opaque intraocular lens procedure is irreversible and removing the implant would involve significant risk of damaging your eye and impairing your vision.