Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Benign Essential Blepharospasm ?
    ### Response:
    Benign essential blepharospasm (BEB) is a progressive neurological disorder characterized by involuntary muscle contractions and spasms of the eyelid muscles. It is a form of dystonia, a movement disorder in which muscle contractions cause sustained eyelid closure, twitching or repetitive movements.
    