As we age, our skin becomes looser.  This frequently leads to an excess of skin in the upper eyelids causing them to droop.  This is referred to as Dermatochalasis.  This is a very common problem.

Also, fat around the eyes sometimes herniates through the septum resulting in fat pockets or "Bags" under the eyes.

Blepharochalasis is the condition where the skin is stretched by frequent allergic swelling of the eyelids.

Both conditions are treated with surgery (Blepharoplasty).