Why do we get bags under our eyes?

The skin around the eyes is only about 0.5 millimetres thick, much thinner than on the rest of the face. With age, the tissues and muscles supporting the eyelids weaken, and fat that normally cushions the eye can move into the lower lid area, causing puffiness. Fluid can also pool overnight, especially after salty food or alcohol. Dark circles appear when blood vessels show through thin skin or when sun exposure increases pigmentation. Allergies, genetics and lack of sleep all make bags more noticeable. Cold compresses and sleeping with the head slightly elevated can reduce mild puffiness.