Re: anyone beeten the dark cycles/ tired looking thing?
Lack of sleep should definitely be the first thing you rule out. If you don't sleep enough then that could be the cause. However there are many other ones.
They don't always have to do with age either. I've had problems with dark circles since I was 13, so for me it didn't start with age. I simply have especially thin skin beneath my eye, so It's very noticeable on me. So I end up being more sensitive to the causes then others.
I've heard that staring at a computer screen all day can cause dark circles, Although I'm not sure on the science behind it.
Lack of vitamin C can contribute, I buy (Cod liver oil) Pills to make sure I get mine. It's most effective for dark circles if you poke a hole in the caplet and then squeeze the oil out, then apply it to your dark circles directly, although swallowing will have positive effects as well. These are actually relatively cheap, I pay like 7 bucks for 90 pills.
Sinuses can cause dark circles as well, Sometimes it's barely even noticeable that there's a problem with them. I use Breath right nasal strips to help with that, although I find them a bit too expensive so I don't use them every night. Nasal irrigation tools can help sinuses as well, Warm water will loosen things up and clear them out, but it's more beneficial to your health to use a saline solution(AKA "Salt & Water"). This type of thing is good for anyone whether you have sinus problems or not. It can be as simple as snorting some warm water, or if you wanna add a solution they have cheap devices for such things at your local pharmacy.
There are plenty of other remedies, someone here mentioned tea bags, which I've never tried but It's a persistent theory and many seem to receive positive results. Plus about another 10,000 out there in the ether, many of them actually work, some time spent surfing will flesh those ones out.
Oh and Food allergies can cause them as well.. There isn't really a great way to test for food allergies directly, just trial and error really. Dairy products are a good place to start though.