Yes good luck, smooth green and rough green snakes are insectivores, hopefully they do not rely too much on sight (motion) to trigger feeding responses.
Hm... Is it possible he was bitten by a cat? He looks to have some puncture-like marks on his neck, and I don't think a car would hurt just the eye like that... The reason I ask is because a cat bite has a really high chance of getting infected. Normally I would suggest Neosporin WITHOUT painkillers to prevent infection, but I don't know since it's on the eye.. Does anyone else know if that would be okay?
A good thing to watch is tongue-flicking. Generally a snake doing a lot of tongue-flicking doesn't feel sick. That's probably the best indicator you can just see of whether or not he's got an infection.
I have an adult garter that is blind. Whenever I feed him, I have to knock his food on the glass so he can locate it through vibrations and often I have to scent it or tear it open so he can smell it. It's not difficult at all once they get used to being hand-fed.
Good luck with him and keep us posted!
Lora
"When one tugs at a single thing in nature, he finds it attached to the rest of the world." - John Muir
1.1 T. sirtalis sirtalis