We've all been there once (or twice). You spend all night drinking margaritas, and the next morning, the evidence is written on your face. Under-eye bags and darkness are noticeably worse after you've skipped a few hours of sleep. Insomnia can cause your blood vessels to dilate, making the under-eye circles more obvious. Puffiness can also be attributed to bad rest. Next time, place a few pillows underneath your head, so you're sleeping with your face at an angle.