An eye twitch is an involuntary tic, a minor eyelid spasm. The condition can be unexpected and annoying but it's not painful. The twitch usually affects the bottom eyelid, although it can also occur in the top lid. The causes are usually minor and do not signify a serious medical issue. In a few situations, more serious causes are found, usually involving additional facial movements or pain.
Stress
Exhaustion and stress can cause an involuntary twitch, which usually goes away when you relax or get a good night's sleep. Strain from too much computer work, reading or detailed work can strain your eyes. Sometimes bright lights can also trigger a twitch.
Caffeine, Alcohol or Allergies
Too much coffee, chocolate or tea can cause an overload of caffeine and stress. Alcohol can also affect the system. Allergies, with the resultant itching or swelling, could lead to an eye twitch as could dry eyes or other irritants in or near the eyelid.
More Serious Disorders
Twitches that involve more than just the eyelid, with facial or other inadvertent movements, can be related to more serious neurological disorders, for example Parkinson's disease, Bell's Palsy, or Tourette Syndrome. Medications that treat other conditions such as epilepsy can also cause twitching. Most eye twitches do not become worse and end on their own. If they don't, or if other conditions occur such as swelling, drooping lids or twitching beyond the eyelid, see your physician or an eye specialist.
