Benign essential blepharospasm (BEB) is a progressive neurological disorder characterized by abnormal blinking or spasms of the eyelids. It is a form of dystonia, a group of movement disorders involving uncontrolled tensing of the muscles (contractions), rhythmic shaking (tremors), and other involuntary movements. BEB occurs in both men and women, although it is especially common in middle-aged women. Initial symptoms include an increased frequency of blinking, dry eyes, and eye irritation. As the condition progresses, spasms of the muscles surrounding the eyes cause involuntary winking or squinting and increasing difficulty keeping eyes open, which can lead to vision impairment. In more than half of all people with BEB, the symptoms affect other facial muscles and muscles in other areas of the body. When people with BEB also experience involuntary muscle spasms affecting the tongue and jaw, this is known as Meige syndrome. The cause of BEB is unknown; however, some cases appear to run through families.