Double vision, also known as diplopia, is a condition that causes people to see two images of an object. A variety of conditions cause diplopia, including strabismus, cranial nerve palsies, multiple sclerosis, myasthenia gravis, orbital injury, stroke, and intracranial tumor.
Treatment for double vision depends on the underlying cause.

For more information from other health sites, please visit the following webpages:
Brigham and Women's Hospital, Double Vision
http://www.brighamandwomens.org/Departments_and_Services/neurology/services/NeuroOphthamology/DoubleVision.aspx

Merck Manual, Diplopia (Double Vision)
http://www.merckmanuals.com/professional/eye_disorders/symptoms_of_ophthalmologic_disorders/diplopia.html