
Your own vet will refer your dog for treatment, to one of the veterinary eye specialists. It could mean a lot of travelling. Your best course of action is to discuss this with your vet and perhaps go to an eye testing session where a veterinary opthalmologist is testing eyes. They would be able to give you a detailed answer as to whether it will be worthwhile, and whether it will improve things for your dog.
Having said that do remember that dogs use sense of smell as much if not more than sight to get around anyway.