Hey Amov,
I also suffer from the same ailment, dark circles under the eyes. I too sleep between 8 and 10 hours every night, and have noticed the circles seem worse with the more sleep I get. I eat healthy, exercise, and have an emotionally and spiritually healthy lifestyle with minimal stress. When I sleep between 5-6 hours from 12:00am -6:00am I find the circle are less pronounced. It must be deep sleep though, where I'm dreaming.
From my research it seems that these circles can be the result of a combination of a sleep disorder (too much or too little, no deep sleep, etc.), iron deficiency, elevated stress, kidney yang imbalance (traditional chinese medicine), sinus congestion. Other possible causes include intestinal parasites(tapeworm) and allergies (hay fever, etc.). Most likely it is a combination of some or all of these in varying amounts.
I have read some studies that conclude that too much sleep is often the culprit behind the dark circles. When we lie down, gravity causes fluid to gather in our lower eye lids, causing the eyelids to swell, thus creating shadows under the eyes which accentuate the circles. Also, thinning skin below the eyes allow the vascular structures to become more apparent. Dark circles can also be genetic. Another extremely important factor is hydration. Most people don't get enough fluids. A good gauge is the color of your urine. If it is constantly yellow to dark yellow, and hot, with a strong odor, you might not be getting enough fluids. This can cause dark circles under the eyes.
So, to conclude here is what I do:
•I decrease sleep to no more than 7 hours a night. 5-6 is prime and plenty to give me the energy I need. (I use the gauge of 2:1, sleep:exercise) here is a link to an interesting study
http://news.bbc.co.uk/1/hi/health/1820996.
stm
•Increase excercise to at least 2 hours of solid excercise or movement (walking, gardening, basketball, etc.) especially at a younger age, such as 15, one should be getting at least this. Humans are made to move.
•Make sure my body is getting enough water and oxygen. Excercise allows oxygen to reach muscles and tissues, increasing circulation. Breathing excerices also help to get the blood and oxygen to the right places.
•Eat more fresh,raw food. Simple. We need to eat things that still have life in them in order give our bodies life.
•Make sure I'm getting enough iron and vitamin C, taking supplements if necessary.
•Smile more, as it gives my facial muscles excercise and keeps the blood in my face moving. Also, when I'm smiling the circles become less visible as the muscles push them up, plus my mouth becomes the focal pint of my face, thus helping to keep up my self esteem.
I hope this helps your ailment!
Best,
helpinghand