orbicularis oculi muscle
The orbicularis oculi is subdivided into orbital, palpebral and lacrimal parts.
Each has defined actions.
The orbicularis oculi is secured to the medial and lateral palpebral ligament forming a ring in the eyelid tissue centered about the anterior eye. It also inserts on the eyelid 'skeleton' the tarsal plate. It forms connections between the superficial muscular aponeurotic system (SMAS) of the face and frontalis, the temple and the cheek.
The orbital part forms the bulk of the muscle, can squeeze the eyelid closed tightly and is used in bright light.
Has thinner fibers continuous with the orbital part. It functions to lightly close the eyelid.
Forms a small slip originating adjacent to the lacrimal gland to insert on the lateral eyelid. It is thought to promote flow within the gland.