Upper eyelid

Palpebra superior

Sensory (eye & ear)SkinHeadLeft and right

View left in 3D View right in 3D

What it is

A mobile fold of very thin skin over a layer of orbicularis muscle, a stiff tarsal plate and the palpebral conjunctiva. Its margin carries the lashes in front and the openings of the meibomian glands behind; a skin crease marks where the levator aponeurosis inserts.

Function

Protects the cornea, spreads the tear film with every blink (15-20 per minute) and shuts out light during sleep.

Size

Covers the top 1-2 mm of the cornea; crease ~8-10 mm above the margin; lid skin <1 mm thick, the thinnest in the body.

Clinical note

A drooping upper lid (ptosis) can come from a stretched levator aponeurosis, a third-nerve palsy, Horner syndrome or myasthenia gravis.