Whats the deal with sunken eyes?

So lately I’ve noticed my eyes looks very “sunken”? I don’t know if it is coming with age (im 23) Lack of sleep(i’m lucky I get about 5 hours a night) or something else. To give a better example, here is a pick I found via Google image search:
http://i36.tinypic.com/2ro3lw4.jpg

My apologies to whoever this girl is for calling you out like this….

My eyes much like her’s have that line under them almost my it puffs up near the sinus area, although lately i’d say it’s a bit worse then her’s is. I don’t like it at all, does anyone know what could cause this or if there is a way to correct it(without surgery)?

I drink alot of fluid and each vegetables and fruits often.