Why do you get bags under your eyes when you're tired?
What are the bags under your eyes when you get tired? Is it a facial marking evolved to warn people away from crabby bad sleepers?
Felicity Bedford enlisted Dr Sean Lanigan, president of the British Cosmetic Dermatology Group to help with this eye opener.
Sean - The eye bag area covers the lower orbital rim where the whole in the skull accommodates the eyes. The skin underneath the eyes covers muscles, fat and blood vessels. Because it is so thin, it is relatively transparent so you can see through to the tissues underneath. The main changes people notice in this area are dark circles and puffiness.
Felicity - I certainly notice dark circles in the morning. Why are some people lucky and always seem to be fresh-faced?
Sean - Dark circles are often seen in people with familial or genetic tendency to have them. How dark that area is can be to do with your skin pigments, and if you rub tired eyes you can thicken the skin and make it look puffy and darker. Another factor contributing to dark circles is blood, which is red, blue and purple pigments. These colours are seen through the skin and can change with skin thickness. The body responds to tiredness by making hormones to help boost energy levels, such as cortisol. These hormones result in more blood in the skin, enlarging blood vessels and retention of water, which all contribute to darker circles and puffiness. Lifestyle choices such as late nights, excessive alcohol and coffee consumption will all influence cortisol levels running the risk of puffy, dark eyes.
Felicity - I think I'll be going to be bed early to try and shift my dark circles now. Well, puffy eye bags don't seem to serve a purpose. Is James correct in thinking eye bags are a reliable warning of someone who's in need of a good night's sleep?
Sean - Sadly, puffy eyebags are more common as you get older as changes in elastic tissues and collagen mean the skin is less elastic and stretches. The pads of fatty tissue found in your eye socket creep downward over time. This is worse in people who've had a lot of sun exposure on their face. Whatever your age, water moves in and out of the skin through the day and night; this is helped by gravity and the heart pumping blood around. When we lie down, fluid sits in the loose eyelid skin as there's no help from gravity to move it, so eye bags are often more obvious after a night lying down, whether we sleep or not. Over time the effects of gravity will slowly cause bagginess which will be persistent.
Felicity - Thanks Sean. So James, eye bags are not always a sign that you need a nap. In fact, depending on the cause, lying down could actually make puffy eyes worse.
Our next question is from Ghayath..
Ghayath - Why do humans have such a variety of appearances?