Blepharospasm or eye twitching is believed to be caused by an abnormal functioning of certain nerve areas located at the base of the brain which control the coordination of muscle movements. In the majority of people it appears without any real known cause. Frequently, the signs and symptoms of dry eye occur right before or along with the appearance of eye twitching. Some research indicates that dry eye is a trigger for blepharospasm in those people who are may develop it. Occasionally eye twitching may run in families or be side effect of certain medications.

Other common causes of blepharospasm include:
Stress
Irritation of the Cornea or Conjunctiva
Fatigue
Lack of sleep
Prolonged staring at a computer screen or television
Nervous system disorders