Thanks for all your responses guys. He's home and sleeping on my bed now, but his eye is too swollen to really be able to tell if he's blind in it or not, it is not looking too good though
I have to put medication cream on it all the time and he yelps so much I almost cry, and he doesn't seem to want to drink so I've been having to use an injector thing to force it. Other than that his attitude hasn't really changed, which is one thing I was really scared of, and I took him for a walk today and he wasn't fearful of any dogs we passed. This decision is keeping me up right now though. I'm the kind of guy who will go way out of the way to catch a spider or moth and put them outside rather than just squishing them, but I do believe that this dog is dangerous, and that this could and likely will happen again. And I feel like reporting it to the SPCA is equivalent to giving it a death sentence. But I will wait until the bills have been paid, and at the very least will tell him to get a muzzle and that if my friend sees the dog without it on that I will head right to the SPCA. Again, thank you for the advice and for giving me the chance to get all this out, I really appreciate it.