The orbicularis oculi muscle is a ringlike band of muscle, called a sphincter muscle, that surrounds the eye. It lies in the tissue of the eyelid and causes the eye to close or blink. At the same time, it compresses the nearby tear gland, or lacrimal gland, aiding the flow of tears over the surface of the eye. Contraction of the muscle also causes the appearance of folds or crow’s feet that radiatemycontentbreak out from the outer corner of the eye.