Blepharospasm is an involuntary closure of the eyelids.

The cause of benign essential blepharospasm is unknown. Blepharospasm is not caused by a problem with the eyes themselves, but rather with the brain regions controlling the muscles of the eyelids.

Secondary blepharospasm occurs due to some identifiable cause. The most-common cause of secondary blepharospasm is a reaction to antipsychotic medications, and is called tardive dystonia.

The medical term for this phenomenom is blepharospasm, and it is any abnormal tic or twitch of the eyelid. It normally refers to benign essential blepharospasm, a neurological movement disorder involving involuntary and sustained muscle contractions of the muscles around the eyes. Benign means the condition is not life threatening. The cause is unknown, but fatigue, stress, or an irritant are possible contributing factors. Some drugs can induce blepharospasm, such as those used to treat Parkinson's disease, as well as sensitivity to hormone treatments, including Estrogen replacement therapy for women going through Menopause. Blepharospasm can also be a symptom of acute withdrawal from benzodiazepine dependence. In addition to blepharospasm being a benzodiazepine withdrawal symptom, prolonged use of benzodiazepines can induce blepharospasm and is a known risk factor for the development of blepharospasm.

Blepharospasm has a number of symptoms. These include sensitivity to bright lights, escessive blinking and spasming of the eyes, dryness of the eyes, and uncontrollable twitching of the eyes and facial muscles.