Orbicularis oculi

The orbicularis oculi (Latin: musculus orbicularis oculi) is a circular-shaped facial muscle located around the opening of the eye. This muscle is classified as the circumorbital and palpebral muscle. Among other functions, the orbicularis oculi muscle is involved in closing the eyelid.

The orbicularis oculi is composed of three parts - orbital, palpebral and lacrimal. The orbital part lies circularly around the orbital opening. The palpebral part is situated in the upper and lower eyelids, while the lacrimal part lies most deeply.

All parts of the orbicularis oculi muscle are innervated by the branches of the facial nerve (CN VII). The arterial blood supply of this muscle is provided by the branches of the facial, superficial temporal, maxillary and ophthalmic arteries.