The most common things that make the muscle in your eyelid twitch are fatigue, stress, and caffeine. Once spasms begin, they may continue off and on for a few days. Then, they disappear. Most people have this type of eyelid twitch once in a while and find it very annoying. In most cases, you won't even notice when the twitch has stopped.
More severe contractions, where the eyelid completely closes, are possible. These can be caused by irritation of the surface of the eye (cornea) or the membranes lining the eyelids (conjunctiva).
Sometimes, the reason your eyelid is twitching cannot be found. This form of eyelid twitching lasts much longer and is often very uncomfortable. It can also cause your eyelids to close completely.