Re: How do black rings under the eyes of tired humans develope?

Thomas,

A person does not necessarily need to be tired for dark circles to be
present. A genetic component can predispose someone to have these circles
present.

Actually what you are seeing is an accumulation of fluid around the eyes
which gives a dark appearance. The skin is very thin in this area. You 
might
be seeing just some stasis of blood.in the tissues. Certain diseases also
can cause this phenomenon. I would check with your family doctor regarding
those diseases.

More information can be found although mostly from a cosmetic level, if you
search "dark circles around eyes" I did not cite them, since they appear
more in the advertising arena.

I trust this will support additional research on your part to learn more
about this interesting topic.

Thank you for your question.

Linda