An eye twitch is an involuntary spasm of the muscles in the eyelid. Blepharospasm is the medical term for eyelid twitching. Eyelid twitching usually occurs every few seconds and lasts for a few minutes. It may come and go over a period of days or weeks. Sometimes the twitching results in the eye being held closed until the movement stops, but this is not always the case.
In most cases of eyelid twitching, no identifiable cause can be found. However, certain environmental and behavioral factors may worsen eyelid twitching, such as caffeine consumption, stress, and smoking. Eyelid twitching may also accompany irritations or infections of the eye. In rare cases, eyelid twitching, usually when accompanied by other disordered movements, can be a symptom of a chronic neuromuscular disorder such as Tourette's syndrome. Benign essential blepharospasm is a rare, benign condition characterized by abnormal blinking movements in both eyes. Hemifacial spasm involves involuntary movements of the muscles around the eye and mouth on one side of the face only.
Eye twitching is typically not associated with pain and is usually only a mild annoyance. Visual disturbances do not occur unless the eye is forced shut by the spasm. Typically, the spasm goes away on its own without the need for treatment. Botulinum toxin (Botox) injections have been used to relieve eye twitching in chronic conditions such as benign essential blepharospasm and hemifacial spasm.