ANOTHER HEALTH QUESTION ABOUT EYES?

My friend who is 40ish, has been having some vision problems lately... He says especially when he is in the dark, his eyes start to go gray, almost like he is losing his vision...scary! But as soon as he turns on a light he says it gwts better. No vision problems up until now~ Another, he can be looking at like a computer screen and things go unfocused and a little blurry, no double vision.. What do you think? Has neck problems(Cervical Degenerative Arthritis) Thanks for the input~