Finally, some real advice.

I read an article on dark circles in Realsimple.com. Pretty good site. Lots of handy little tips we can use.

According to this NYC dermatologist, sleeping "may help diminish their appearance a bit". MAY. Rather disappointing..

Dark circles appear because of genetics (thin or fair skin), age, and seasonal allergies. It also appears because there's a lack of circulation caused by lack of sleep.

So they suggest to prop on more pillows to "stop blood from building up under your eyes". Then apply something cold to constrict the vessels in the morning. If thin skin is the source, they suggest to take to apply collagen creams.