Although it would be helpful to see photos and know what operation you actually had done, I think I can answer your question.
I think you either had an upper blepharoplasty or a eyelid ptosis repair.
A blepharoplasty can be a procedure covered by insurance if there is skin overhanging the eyelashes and physically blocking your visual fields. It involves removing the excess skin from the upper eyelid. There is no surgery on the eye itself. The benefit is removing the physical block from the upper visual fields.
Repair of ptosis is also sometimes covered by insurance. This often involves removing skin as well, but the primary goal is to reposition the whole upper lid in relation to the pupil. This is also a mechanical problem in front of the eye.
In neither case should you expect a change in your visual acuity. Unless you also had an operation on your eye itself, ie lasik, cornea transplant, glaucoma procedure, at the same time, your vision should not change. Your prescription for your glasses is independent on the operations on your eyelids, and is not related.
I would recommend speaking with your surgeon and your ophthalmologist about these issues.