Is My Pet Ferret Blind, Or Just Crazy?

Okay so I have a approximately 4 year old pet ferret Ralph. We rescued him from abusive owners when he was one, and he’s always been a few puppies short of a pet shop. He's also very small compared to my other 2 year old male Milo. He was bald for a good chunk of his life and then last year he just.. poof grew back his fur, longer than ever. After that happened his eyes have been getting gray and foggy, which is wrong ferrets should have clear black eyes or red. He bumps into things and he slips when he walks. Also his back left leg seems to spazz out on him a he just doesn’t use it sometimes. Seeing as this is not life threatening and Veterinary services for ferrets are very high we have not had him examined recently. So blind crazy or both?