Eyelid Muscles
Levator and Orbicularis

The main muscles of the eyelid are the levator muscle and the orbicularis muscle.

The levator muscle is main opening muscle of the upper eyelid. It originates in the back of the socket, extends forward through the orbit above the eyeball, then enters the eyelid itself, where it turns into a tendon, or levator aponeurosis, that attaches to the eyelid. If the levator muscle becomes paralyzed, the upper eyelid droops (ptosis).

The orbiculairs muscle is the main closing muscle of the eyelids. It is a large circular muscle that surrounds the upper and lower lids and extends slightly onto the brow and upper cheek. If the orbicularis muscle becomes paralyzed, the eyelid cannot close.