your body gives you clues as to what it needs. dark circles is the bodies way of saying you need more restful sleep. you could have a check up with a doctor and blood work done to see if everything else is okay. fingernails can tell you if you are anemic or if you have high chloestrol, high blood pressure, and a lack of vitamins. the body is amazing. you already know if you sleep more your eyes look better. listen to what your body is telling you.