I also have a blind chick, If yours is weak get some poly vi sol (no iron) into him, I made a chick starter soup so I knew he would get both nutrition and water. He now has a small flat rock that is placed in front of his water, when ever he stands on the rock he puts his head down looking for the water. I keep him in the the "just hatched" chicks. Good luck with yours, hope you don't have to cull him 
