Help with rescued one-eyed oranda please!!!?

I went to my aquarium on thursday to buy a new oranda. they had one that a lady had 'traded in' cos she didn't want it. he's really sweet, but only has one eye. during his first night he got wedged upside down by the filter tube, i don't know how long he'd been stuck for. i freed him by moving the tube and he just lay on his side on the floor, gasping and breathing really fast for about 5 mins. then he got up and went to the top of the tank and his breathing slowed down to normal. i put melafix in the water as he lost a few scales during his accident and his skin looks fine, not red. He's not hiding now, since yesterday morning he's been swimming around fine, but won't eat, and he hasn't been anywhere near the bottom of the tank. he just swims to and fro, near the top of the tank but doesn't appear stressed? (apart from a few red streaks in his tail fins, but not too bad) he's not gasping for air, he's a couple of inches from the top. i've tried feeding floating flakes, brine shrimp, veggie flakes, anything to tempt him but he just swims straight past it. i don't know if he can see out of his one eye or not. I'm so worried that he's not eating, my other fish aren't bothering him at all. I don't want to move him into a 'hospital tank' for fear of causing him further stress, please advise! He's about 4 1/2 inches long so he's not a young fish. should i just leave him alone and hope he starts feeding? i've kept the tank lights off more than usual, but the light doesn't seem to bother him anyway. i tried hand feeding a bit of watermelon but he just swims straight past my hand. Help please!