levator palpebrae superioris muscle

The levator palpebrae superioris muscle retracts the eyelid to "open" the eye.

The main muscles, in the upper eyelid, that control the opening and closing are the orbicularis oculi and levator palpebrae superioris muscle.

Damage to the levator palpebrae superioris muscle causes ptosis, or drooping of the eyelid, when the muscle can no longer hold the eyelid up.

The superior tarsal muscle is a smooth muscle adjoining the levator palpebrae superioris muscle that helps to raise the upper eyelid.

Also muscles that are responsible for opening the eyelid: levator palpebrae superioris muscle and the superior tarsal muscle (Muller's muscle) will not work.

In this case, the ptosis is due to the result of interruption innervations to the sympathetic, autonomic Muller's muscle rather than the somatic levator palpebrae superioris muscle.

It enters the orbit via the superior orbital fissure and controls most of the eye's movements, including constriction of the pupil and maintaining an open eyelid by innervating the levator palpebrae superioris muscle.

By observing the eye movement and eyelids, the examiner is able to obtain more information about the extraocular muscles, the levator palpebrae superioris muscle, and cranial nerves III, IV, and VI.

Abadie's sign of exophthalmic goiter is Spasm of the Levator Palpebrae Superioris muscle with retraction of the upper lid (so that sclera is visible above cornea) seen in Graves-Basedow disease which, together with exophthalmos causes the bulging eyes appearance.

Failure of CN III will result in loss of function of the following eye muscles: medial rectus, superior rectus, inferior rectus, as well as muscles that are responsible for opening the eyelid: levator palpebrae superioris muscle and the superior tarsal muscle (Muller's muscle).