How do you feed a blind fish?

I have a 4-5 year old oscar who I believe is mostly blind. One of his eyes is not sharp in color and has red dots in it near the bottom. Today when I tried to feed him( for the first time since his tank mates were removed) I noticed that he was bumping into the ornaments in the tank and he would not come up to the top of the water nor would he pay any attention to the pellets being dropped in the water. I am concerned b/c this is unusual behavior for him. Normally he would come right up to the top of the tank and you could drop the food right in his open mouth. What am I to do if he really is going blind?