Ocular myokymia, more commonly known as eyelid twitching, is characterized by contractions or twitching of the eyelids. According to the North American Neuro-Ophthalmology Society, eyelid twitching involves jumping of the eyelids. It can last anywhere from a few seconds to a few days, while in rare cases, people can experience it for weeks and months at a time. According to John Swogger, DO, an ophthalmologist at the UPMC Vision Institute, an episode of myokymia may feel as if the eyeball is twitching or shaking. The experience also may feel like fluttering from above and below the eye itself; however, it is rarely associated with movement of the eyeball. The condition can happen at any age and usually only in one eye at a time, though both eyes can become involved. It usually affects the lower eyelid, but both can be affected.