@Batsylee no no.. dark circles can be not only because of less sleep, but also of less level hemoglobin in your blood. It can be quire serious, believe me. So if you feel tired all time, your face is pale, you don't have mood and strength to go somewhere, live an active life, you can have a lack of hemoglobin. Make your blood test to know about it.
You are right, Batselee, that dark circles can be because of this. However I think that despite the fact all of us live very busy lifes, we shouldn't forget ourselves, even you are young lady who can be glad of her nice looking:) So supergirl, don't be super girl, be a girl who can present for herself a super time;)