My 7 year old nethie became blind about 3 months ago. She's been a real trooper about it. After a few weeks you couldn't tell she can't see at all - most people don't believe me when I say she's blind. You just have to help her by doing obvious simple things : speaking when you come into the room, make noise when you put food or something new down, try to leave things at the same place so that your rabbit won't have any trouble to move around. Of course, don't move your rabbit unless it is absolutely necessary because to put him on the floor suddenly will desorientate him. But honestly, I'm amazed by how well Aki has been doing : she followed the walls, often put her muzzle on her husbunny to check where he was and hesitated a bit while moving during about a month (she was very stressed too, she even had a bout of GI stasis - during this time, I mainly left her alone with her bunny friend, closing the door to their room so that there were no strange noises that could startle her and I made several piles of hay on the floor so it was easier for her to find it) but after that she got used to it very fast. Now she's running around like before. A month ago, we went to my parents' house for the holiday, where she hadn't been for a year, and she went into her cage and little cardboard houses with no hesitation whatsoever (even those with a second floor!) - some things had been moved but she memorized everything after a single tour of the room and I've never seen her bump into anything. She's now back to her feisty, picky self and will fight her husbunny bravely for the last piece of carrot or a few pellets (even without her sight, she's still winning most of the time).
So, I wouldn't really worry about your rabbit. Check that he can access his food easily, try not to startle him and he will get used to his new situation in no time at all.
