I'm 31. I have had an extra bag of fat under my right eye (left in the picture) for as long as I can remember. It's more obvious when I smile and when I am tired, but it is always there and has always only been on that side. What is it, why is it only on one side, and what must be done to make it look more like the other eyelid? I don't see many pictures of people with one eyebag!