Has anyone ever had a surgical eyelid lift on one droopy eye only?

Droopy eyelid. This is a condition that can be treated with surgery on the droopy eyelid only or in conbination with other eyelid surgery.
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.
Rare. It is rare to fix one eye unless you have ptosis. If only one eye droops see an oculoplastic surgeon for repair.
Yes. If one eyelid is droopy, that is a condition called ptosis. It can be corrected as a stand-alone procedure without having to have any surgery on the other eye. Consult with good, experienced plastic surgeon or an oculoplastic surgeon. Be well.