Eyelids: Function, Structure, and Importance in Eye Health

Eyelids are the two folds of skin that cover the front of the human eye. They protect the eyes from dust, dirt, and other irritants. They also help to spread tears over the surface of the eye to keep it moist. The upper eyelid is mobile, which is why you can blink your eyes. The lower eyelid is less mobile but it does contain the lower tear duct.