Droopy eyelid. There are several causes of a droopy eyelid. Your best bet would be to have your eyes evaluated by a board certified facial plastic surgeon.
With surgery. Droopy eyelid can mean either excess skin hanging over the upper eyelid (dermatochalasis) and/or sagging of the upper eyelid edge (blepharoptosis). Dermatochalasis is corrected w/ blepharoplasty, where the excess skin is excised. The scar hides well in the upper lid crease. Blepharoptosis is corrected by tighening the muscle that lifts the lid. This is done via lid crease or conjunctival incision.