Let us count the ways, in descending order of frequency:
Heredity: That’s right. It wasn’t that night on the town that makes you look like a raccoon in the morning. It’s all your parents and grandparents’ fault. Some people are born with excess fatty tissue and liquid around the eyes.
Fluid retention: The eyelids are the thinnest and softest skin in the entire body, four times as thin as “average” skin. Fluid tends to pool in thin portions of the skin.
What causes fluid retention? Among the culprits are drugs, kidney or liver problems, salt intake, and very commonly, allergies. Cosmetics drum up more business for dermatologist and allergists than just about anything else. Allergic reactions to mascara and eyeliner are the usual culprits.
Aging. The skin of the face, particularly around the eyes, loosens with age. Age is more likeliness to cause bags than mere sleepiness or fatigue.
Too many smiles and frowns. These expressions not only can build crow’s feet but bags. We can safely disregard this answer to explain Bob Newhart’s bags, however.
Another less fascinating explanation for many sightings of bags under the eyes are noted by Dr. Tom Meek, of the American Academy of Dermatology, in the New York Times: “The circles are probably caused by shadows cast from overhead lighting…”
Submitted by Stephen T. Kelly of New York, New York
From: When Do Fish Sleep? by David Feldman