The Eye Institute©

The Eye Institute©

Double vision, also called diplopia, causes a person to see two images of a single object. There are two types of double vision: monocular and binocular.

Monocular diplopia is double vision in only one eye. The double vision continues even when the other eye is covered. The doubling does not go away when you look in different directions. Monocular diplopia can be caused by astigmatism, keratoconous, cataracts, diclocated lens implant, swelling in or around the eye, dry eyes, and/or some retinal problems.

Binocular diplopia is double vision related to a misalignment of the eyes. The double vision stops if either eye is covered. Any problem that affects one or more of the muscles around the eyeball that control the direction of the gaze can cause binocular diplopia. These are called extraocular muscles. Strabismus, damage to the nerves controlling extraocular muscles, diabetes, Myasthenia gravis, Graves’ disease, and/or trauma to the eye muscles are also some causes of binocular diplopia.

Symptoms
The only symptom is seeing two images of a single object.

Diagnosis
The first step is to determine whether your double vision is monocular or binocular. To do this, your doctor will ask you to cover one eye and then the other. If you have monocular diplopia, your doctor will evaluate you for conditions, such as cataracts, that could be causing the problem.
In diagnosing binocular diplopia, your doctor has to determine which eye muscles are affected. Your doctor will use the results of this exam, together with your medical history and additional symptoms, to determine if you need more tests.

Expected Duration
How long your double vision lasts depends on what is causing it. For example, cataracts and pterygium may become worse over time, but both can be corrected immediately with surgery. In people whose double vision is caused by diabetes, the nerve often regrows after several months. When this happens, double vision gradually disappears. Children with double vision caused by strabismus can improve with treatment.