PUT MORE LIGHTS IN YOUR DAMN ROOM!!! Arrrgh!
This is from personal experience, curiosity, and much observation:
The puffiness is most greatly affected by lack of sleep - less sleep, more puffy.
The color is most greatly affected by the amount of light in the room. If you are spending hours and hours looking at a computer monitor inside a freakin' batcave, then your eyes will get blackish. If your room doesn't seem dark to you, it may be because you are very used to it. Some people keep their houses very dim - even during the day - and they don't seem to notice how dim it really is.
Note: a 40-watt light bulb does not light a room - use at least 60-75 watts (or its equivalent in fluourescents)
Also, if you're spending a lot of time squinting, quit squinting and get some damn glasses! I squinted all the time until I was 16 just because I didn't want to admit that I needed glasses - until one day a teacher told me I should get glasses in front of the class (humiliating). Glasses help! (or get contacts - cause' they're nice too)
Also, you might not be getting enough liquids.. drink more water.