An eye twitch, while annoying, is usually nothing serious. A twitching eye is a creepy sensation, as you can feel your eyelid moving uncontrollably. What often feels like a huge movement, however, usually can't even be detected by your friends. Many people are familiar with involuntary eye twitching. Eye twitching, or myokymia, is an involuntary eyelid muscle contraction that usually affects the lower eyelid. The exact cause of eye twitching is unknown. A twitch sometimes develops during times of increased stress. Eye twitching has also been associated with high caffeine intake, fatigue or excessive squinting.