The term blepharospasm means is an uncontrolled, abnormal contraction or twitch of the eyelid. Causes may include dry eyes, side-effects from certain medications, sensitivity to hormone treatments, abnormal functioning of the brain basal ganglia or multiple sclerosis.
Hemifacial spasm is a rare neuromuscular disease characterized by irregular, involuntary muscle spasms on one side of the face.This disorder occurs in both men and women, although it affects middle-aged or elderly women more frequently. Hemifacial spasm is much more common in some Asian populations. It may be caused by a facial nerve injury, a tumor, or it may have no apparent cause. Medical evaluation is needed to rule out serious underlying causes.