What's wrong with my dogs eyes?

My 9 year old chihuahua (going to be 10 in about a month) was just recently diagnosed with diabetes. He's a little over-weight by about 5 or 6 pounds. We're been giving him vetsulin (doggy insulin) for the past week and a half now. We caught the diabetes early cause we noticed that he was drinking water like crazy! And he was Urinating like crazy too, even in the house, which is very unlike him. So I'd say he acquired diabetes about week and a half ago or 2 weeks ago or so, well that's when we started noticing his weird drinking/urinating habits. Anyway, he now seems to be having a problem with his eyes. I have been doing some research and I know that dogs with diabetes are more likely to go blind or get cataracts or glaucoma. I'm just wondering if anything out there has/had a dog with diabetes, and even with the treatment, the dog became blind or had alot of eye problems soon after and what did you do or can you do to treat it. (Of course, I'm still going to ask the vet at his next visit.) Thank you in advance.