Blepharospasm is a dystonia where the muscle that closes the eye (orbicularis oculi) contracts uncontrollably. The condition can be severe enough to cause traffic accidents when the patient is suddenly unable to open their eyes to see. The eyes can still be closed voluntarily. Many patients are initially diagnosed as having dry eyes, tics, or simply excessive but normal blinking.

The treatment of choice for this condition is botulinum toxin injections of the orbicularis oculi muscles (the muscle that causes the eyes to close). There are two forms of botulinum toxin available for treatment, type A, Botox®, and type B, Myobloc®. For the occasional non-responders to botulinum toxin injection therapy, one can try anticholinergic medications and some benzodiazepenes.