Why we get dark circles and eye bags

Popular Science 

One's temporary, the other is often built in. A bad night's sleep is far from the only reason we can get eye bags or dark circles. Breakthroughs, discoveries, and DIY tips sent every weekday. Whether it was caused by a night out with friends, a crying baby, or plain old insomnia, we all know that lack of sleep affects our bodies. In addition to fatigue and a yearning for coffee, poor sleep can leave us frowning at the dark, swollen circles under our eyes.