Eyelid

An eyelid is a thin fold of skin and muscle that covers and protects an eye. A muscle is used to slide the membrane over the surface of the eye ("closing" the eye) and to retract the membrane ("opening" the eye). This can be either voluntarily or involuntarily. The human eyelid feature a row of eyelashes which serve to heighten the protection of the eye from dust and foreign debris.

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Innervation

In humans, the ophthalmic branch of the trigeminal nerve provides sensation to the upper eyelid and the maxillary branch of the trigeminal nerve provides sensation to the lower eyelid.

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Eye: : This article refers to the sight organ. See Eye (disambiguation) for other usages....

Muscle: Muscle is a contractile form of tissue. It is one of the four major tissue types, the other three being epithelium, connective tissue and nervous tissue. Muscle contraction is used to move parts of the body, as well as to move substances within the body....

Eyelashes: REDIRECT Eyelash...