* First of June, started him on 14 units of Novolin N 2xday.
* 2 weeks later (over a weekend) he developed bad cataracts. By the time we got him to the vet Monday afternoon (after noticing a problem Friday evening) he was totally blind.
* Middle of June, after vet visits, we increased his Novolin N to 20 units 2x day, then settled on 24 units 2xday.
* The first week in July, we had to board him with the vet for a week - we had pre-planned vacation out of state. While at the vet's, they carefully monitored his blood sugar daily. It looked like the 24 unit dosage was perfect and eliminated blood sugar spikes.
During this time, we had a lot of changes to make in our lives and his.
* Changed his diet
* Established schedule to give him insulin shot, wait 15 minutes, then feed him. This happens every 12 hours.
* We stopped crying and feeling sorry for him (and ourselves) and decided to make the best of the situation. He was coping a lot better than we were.
Duke's Diet:
* Homemade: Stewed chicken, steamed brown rice, carrots, broccoli, cauliflower, green beans. We cook 20# of chicken at a time, mis with cooked rice and vegetables. The mixtured is packed in quart freezer bags. They are kept in freezer and taken out as needed. He gets 1 quart bag per day.
* Dry kibble: We slowly switched to Blue Buffalo Senior Large Breed. He gets about 6 - 8 cups per day.
* Canned Kirkland dog food - maybe 2 cans per day because he really liks it, although the favorite is the homemade stuff.
He's doing great on this diet. His appetite has come back and is maintaining a good weight.
Letting him get his "bearings"
* We found that he did much better getting around if we left him alone and didn't try to talk to him while he was navigating around. Since then, we started using verbal queues like "beep beep" just before we noticed he bumped into something. He stops and backs up. Luckily, he has never been the typical clumsy St. Bernard and is very carefully walking around. He hasn't broken or knocked over anything.
* We have 2 fenced acres where he has always lived (albeit most of the time has been spent in the house
) He has learned how to carefully navigate the 4 steps off the concrete porch down to where we keep his water. He wanders around for a while, does his business, then comes back to the door to "knock" when he wants back in.Scents/Sounds/Sensations:
* His feet are sensitive since he hasn't been running around making the pads tough. This has helped somewhat as he can navigate around our house based a lot on our floor coverings. Certain rooms are tiled, have vinyl, carpet.
* He has always slept by the front door on the tile with his own personal fan. He still lies there. He can hear and feel the fan, and also tell where the carpet ends and the tile begins
* Sounds of our feet. Our house is old and on pier and beam. He follows us pretty well, either by scent our by the sensation he feels as we walk.
* I've always had some wax burners in different rooms, with specific scents in the rooms. He's been used to that and I think it has really helped him know which room he is in, especially on the carpeted areas.
All in all, he's still a blessing and any time we have left with him is precious. He doesn't have any mobility issues, just other health problems that we all face as we get older. When we got Duke as a pup, it was a committment for the rest of his life. We are blessed to still be able to care for him
He's a lucky boy to have y'all!!
I'm glad he has adjusted so well, and that you have a home that is making it easier for him. If he was younger maybe you might want to consider surgery, but 8 is pretty senior for such a large breed dog, and it sounds like he's happy. The "beep beep" is cute! 
You're an angel to do all that cooking. He's a lucky dog!