Benign essential blepharospasm is a common focal dystonia characterized by involuntary eyelid closure. Its etiology, supported by animal models, appears to be multifactorial, representing the influence of a genetic background and an environmental trigger. The genetic background could be responsible for the reduced brain inhibition, identified with physiologic studies that would set up a permissive condition for increased brain plasticity. Reduced D2 receptors identified with PET might be an indicator of this reduced inhibition. The trigger could be repetitive use or local ocular disease. Although symptomatic therapy is available, better approaches are needed and will likely become available as the genetics and pathophysiology become well understood.