The repair of the ptosis can be combined with cosmetic eye lift if needed. The issue of the length of time is the last question to ask. You need to find out about the surgeons experience, talk to other patients and the surgeon approach.
Surgery to correct ptosis (drooping of the eyelid on the eye surface as opposed to excess eyelid skin) usually takes between 30-45 minutes for both sides. I prefer to do the surgery from an external (skin) approach as this is the best way to treat the most common type of ptosis. I also prefer to perform surgery in the office with minimal injectable anesthetic as this allows the patient to open and close their eyes during the procedure. If a patient is under general anesthesia or deep under anesthesia, it will be difficult to judge the eyelid position. This is critical during the procedure. Also, I would always consult a specialist in eyelid surgery for ptosis repair. There are many variables and nuances and, although it seems like an easy and quick procedure, there are many factors to consider.