Severe Eye Injury

Well, I hope its not severe. Tonight, while playing with the dogs, Doc jumped right in front of me as I was swinging a large knotted rope. A knot hit him directly in his left eye at high speed.

He immediately started yelping/screaming/howling and ran away from me. He was in severe pain. Once I got a hold of him, he wouldn't open his eye and was very tender. I finally got it open and saw that it was still movable, in the socket, no blood, and the eye wasn't bloodshot. The only effect I can see is that his pupil is much smaller than normal. It doesn't seem to be light sensitive and he still uses it to see things. I also don't notice any depth perception problems. His lower lid now covers about half of his eye, but I think that's a natural reaction to the soreness he must be feeling.

I feel absolutely horrible about this whole thing and I've been spending a lot of time petting and hugging him. Does anyone else know of something I should look for? Anything I should do?

Thanks in advance.