One of my yorkies in the past also went blind from cataracts caused by diabetes. He was about 11 years old and I don't remember the vet suggesting surgery. It was about 20 years ago. He adjusted OK since he was raised in the house and knew how to get around. But once we moved to a bigger house, we had to keep him in a 'playpen' to keep him safe unless we could watch his every move. If I had to do it again, I would chose having surgery to give him a better quality of life in his last few years. That is my experience. Good luck with whatever you decide.
