noun. 1  a. An old French dance resembling the gavotte, usually in 3/4 or 2/2 time beginning with an upbeat. 2  A movement in ballet in which the dancer transfers body weight quickly from foot to foot, usually on the balls of the feet, in a series of small steps.
Nystagmus is a condition where the eyes make repetitive movements. The eyes can jerk exclusively in one direction, or make back and forth movements. With nystagmus, the eye can look jittery and can affect both eyes or just one eye.
The key to understanding whether double vision is due to a problem in the eye or in the brain is to see what happens when one eye is closed. If there is double vision when looking with the right or left eye alone, then the cause is ophthalmologicalâsuch as a cataract, a problem of the retina, or another eye disease. On the other hand, when double vision is present with both eyes open, but goes away upon looking with only one eye, the cause may be neurological. This type of double vision occurs because of abnormal eye movements that cause the eyes to become misaligned. When the eyes are not aligned properly, one eye sees an image in one location, while the other eye sees the same image in another location.