The cause of blepharospasm is often unknown. It affects women more than men and tends to occur in families. It can sometimes be caused by other eye disorders such as trichiasis, foreign body in the eye, dry eye, and sometimes by nervous system disorders such as Parkinson disease.
Symptoms of blepharospasm are uncontrolled blinking and closing of the eye. In severe cases, people cannot open their eyes. Spasms may be worsened by fatigue, bright light, and anxiety.
If blepharospasm is mild, it may be relieved by simple maneuvers such as singing, humming, touching an eyelid or chewing gum. Otherwise, treatment is injection of botulinum toxin A into the eye muscles, which can relieve or prevent the spasm. Drugs (to reduce anxiety) and sunglasses (to decrease light sensitivity) may help. If injection of botulinum toxin A does not help and symptoms are severe, surgery to cut the eyelid muscles can be done.