Ocular myasthenia gravis is an autoimmune disease that causes chronic fatigue of the eye muscles. It is characterized by a rapid fatigue of voluntary eye muscles that flares up during periods of activity and recedes with periods of rest. It affects both the eyes and the eyelids. Those affected by it often experience double vision and drooping eyelids, a condition called ptosis. Ocular myasthenia gravis is treatable, with treatments including medication, surgery, or the use of devices that help improve eye function.