I would like to recommend my herbal Eye Treatment which will quickly bring your dog's eye health up to its maximum potential. At the very least I would expect to stop further deterioration.
After this with continued use there is the potential to reverse any eye condition including cataract although beyond a certain point I don't expect to get full vision back.
It is certainly the place to start however and the mixture is safe, simple and inexpensive.
The Eye Wash must be diluted. Start with 1 to 2 drops only in 20mls of luke warm water & syringe or drizzle into the eye. If this is well tolerated increase dosage to 3 drops only in 20mls water repeat 3 x a day.