Ptosis is a condition in which the eyelid droops. It is caused by a weakness or separation of muscles deep within the eyelid.
Ptosis does not involve excess skin or tissue in the eyelid (a condition called dermatochalasis). It is usually a result of aging, but some people develop ptosis after eye surgery or an injury, and some children are born with the condition.
A brief surgical procedure can eliminate the drooping.
[All photographs below were taken without Photoshop or similar enhancements]