Repairing the drooping eyelid is often times equal parts training and artform. For example, below is a young man with a droop on the left that was present in later childhood and had not been fixed:
Intraoperatively, this left upper eyelid was intentionally set to be about 3 millimeters (1/8 inch) above the right side. It looks very unnatural to see the white of the eye above the cornea, and it is certainly unsettling to let a patient leave the operating room looking like that. However, repairing a droopy lid (ptosis repair) requires a knowledge of how the injected anesthetic and surgical manipulation can interact with the eyelid muscles. The stimulated muscles often end up lifting the lid several millimeters higher than they really should be, once the anesthetic wears off.
The postoperative week#1 visit showed that the eyelid was still a touch too high. Some exercises were performed to get it just right, as seen in the postoperative month#1 photo: