The medical term for double vision is diplopia. Double vision occurs if the eyes are misaligned, causing two different images to be sent to the brain. The brain accepts both images, resulting in double vision. Double vision can cause problems in life, including great difficulty in completing the simplest tasks.
Luckily, the brain naturally guards against double vision by suppressing, or ignoring, one of the two images. The double vision may seem to disappear when, in reality, one of the eyes is simply not seeing. When vision in one eye is lost, however, a person will no longer have depth perception or the ability to see dimensions.
Double vision can be a sign of a serious neurological problem. Sometimes an injury to the head can cause double vision. Other causes include a stroke, aneurysm, brain tumor, swelling of the brain, cataracts and strabismus. Diabetes, hypertension and multiple sclerosis are common diseases that can cause a temporary paralysis of the nerves that control the eye muscles, which may cause double vision.
If you are experiencing double vision, you should be evaluated by an optometrist, ophthalmologist, neurologist or other medical professional immediately.
Upon evaluation, your doctor will ask you the following questions:
- Did the double vision appear suddenly, or has it been there for some time?
- Is it constant, or does it seem to come and go?
- Does the double vision go away when you cover one eye?
- Do you see double out of one eye, or both eyes?
Double vision may be treated with surgery, medications, vision training or therapy. A prism, a special lens that bends light rays, can also be included in an eyeglass prescription. Temporary prism stickers can also be added to eyeglasses, instead of grinding a prism into the lenses.
Source: Neuro-Ophthalmology - Textbook of Ophthalmology. Slamovits, Thomas L. and Ronald Burd. Copyright 1994, Mosby-Year Book Europe, Ltd.