Granted when ours went blind, he was already starting to crow.But for him, he was used to seeing first, so it really messed him up bad.
If you decide to keep him, see if he can figure out if he wants to live, then by all means help teach him. As you probably know, chickens can be trained.
With Handheld, he learned to find his food by us shaking the dish, touching it to his chest, setting it down, and telling him..bite.
To drink, we splashed the water and told him...drink.
He also knows directions.. forward, up down, left, right, port, starboard, aft.. and backup... man he HATES the words back up.
If you glanced at him, even watched him, you wouldn't know he was blind. Get to talking around him, he's just like an old man, cranky! Then he gets confused, and runs into the fence trying to attack.
Find a baby chick that is way calm around him, let him be the seeing eye chick. That's what one of ours did, she sat underneath handheld and walked with him. To this day, we always have one or two chicks that insist upon staying on the babypen just to take care of him. Handheld takes care of the babies like no other, lol in fact, I dare you to come get one of his babies out of the yard and get away with it. He will find you, and he does sneak better then a snake.
Good luck