Ptosis is drooping of the upper eyelid wherein the muscle that opens the eyelid (the levator aponeurosis) has slipped or is weak.
This is different than Dermatochalasis which only involves excess hanging skin. Upper eyelid ptosis is often seen in conjunction with dermatochalasis where both a blepharoplasty and ptosis repair would be performed. Ptosis repair could be performed from the undersurface of the eyelid leaving no visible scars, or from the front if already performing a blepharoplasty. Either way, the goal is to detach the levator muscle and reattach it further down the eyelid in order to allow a wider opening of the upper eyelid.
This procedure is often covered by insurance depending on the severity of droopiness. Ptosis could also be caused by a nerve problem or from birth. Occasionally if the muscle is too weak a sling procedure would be necessary, connecting the forehead muscle to the eyelid muscle to help elevate the upper eyelid.