WebMD cites fatigue, stress, light sensitivity and lifestyle choices as common causes of minor muscle spasms in the eye. Most eye twitches are simply a nuisance, but in rare cases, they cause more serious effects or are a sign of an underlying medical problem.
Eye spasms, notes WebMD, are typically painless and innocuous. The most common cause is fatigue or lack of sleep. Smoking and alcohol consumption are other possible causes, as is high caffeine intake. An eye twitch might also be a symptom of dry eyes, eyelid inflammation or even pinkeye. In rare instances, it is a symptom of a more serious brain or nerve problem. Bell's palsy and Parkinson's can both cause eye spasms.
Eye twitching is annoying but is typically benign and short-lived. Chronic eye spasms that recur frequently and last for weeks to months at a time are more serious and can affect a person's quality of life. If the spasms cause both eyes to shut completely, the twitch even impairs vision, says WebMD.
Few treatments exist for eye spasms, since most go away on their own. WebMD suggests that botulinum toxin is a potential treatment for chronic eye spasms. However, the effects eventually abate and more injections are necessary.