Minor differences are for the most part not detected. Rarely has a difference been obvious enough for anyone to choose to have further surgery. In some cases the position of the lid edge is hidden by the excessive skin or wrinkles. Unequal positions of the lid edge can be present and hidden. Eyelid surgery may also make muscle weakness of the lids more obvious.
Some people have weak lid muscles.
When they become tired the lid can droop. If both lids droop then the problem is less obvious than if one lid is weak. Since muscle weakness comes and goes, it may not be present when you are examined. This has not been a significant problem for those who have such a condition but let us know if you have observed muscle weakness in one or both eye lids. Most people do not realize that eyebrows have an important role in the way our eyes and faces look.