Why does my cat have brown ish watery eyes?

my cat is fairly old, I got him when i was in the 2nd grade and now im in 10th. But, almost all the time he's had these eye boogers constantly. but they're like a brownish reddish color. I always wipe them out but they come back, like little tear drops then they turn crusty. I can't remember him ever not having this problem. & if it's something serious i cant take him to the vet because i dont have that kind of money. One of my friends said he could be going blind, but since he's always had this problem, he would have gone blind by now?.. So what is this, and how can i take care of it myself?