There are two 'main' surgeries that might be performed on the upper eyelid.
This section addresses Ptosis  which is the medical term for drooping of the
upper eyelid; it might affect one or both eyes.

The other surgery of the upper eyelid addresses excess skin  is repaired by blepharoplasty.

Ptosis occurs when the muscles that raise the eyelid (levator and Müller's muscles) are not strong enough to do so perfectly. It can affect one eye or both eyes and is seen more frequently in the elderly, as muscles in the eyelids might begin to deteriorate.