I remember how upset I was when Josh started to go deaf at about the same age as Woofie, so I understand what it feels like Lisa. He also had a heart murmur and heart failure diagnosed at about 10 and 12 years of age, but they were both really well controlled by medication so didn't cause him any problems.
You say that Woofie is also developing cataracts, but they haven't advanced much yet. Josh also started to develop them, but when he was about 13. I discussed them with the vet and because they were slow developing decided not to have them operated on. Although his heart problems were very well controlled, a general anaesthetic would have been quite risky and I agreed with the vet that as he was already 13, it was probable that something else would carry him off before he went blind with the cataracts.
With hindsight that maybe wasn't the greatest decision as Josh lived until he was 16 years and 51 weeks. He was completely deaf for the last 6 or 7 years of his life and coped with that really well, but he lost the sight in one eye when he was about 15 and the other one about 8 months before he died. So I had a deaf and blind spaniel
. But he was still eating well, enjoying his cuddles and being close to people and pottering about in the garden. He didn't have mobility problems apart from being just a little bit slow to get up after he'd been sleeping and as he approached the end he slept most of the time anyway. I thought about the quality of his life every day, and each day decided that as long as he was pain free, eating well and enjoying all the cuddles he had, then he still had a reasonable quality of life.
But I do wonder if I should have risked the cataract operations. I don't give myself grief about it, because I did what I thought was best, but I reckon he would have been a bit more active in the last year of his life if he'd still had a bit of vision.