Used to have a super chill Collie/Rottweiler mix. She was a bit of a gentle giant. She'd always get close to other dogs in the dog park to say hello. And she's got whacked in the face or barked at by a littler guy and would be super cool about it just not really care. Everyone loved her.
She's a bit of an ol' grandma now though. And the old room mate adopted her when I moved and is taking care of her now at her place in the woods.
Full blind though, from diabetic problems we suspect. We never really let her get fat, just genetics. And vet didn't really figure that out till way later and just called it suddenly blindness syndrome when she went blind at the time. So if your dogs eyes ever start going bad and some vet feeds you sudden blindness syndrome. Just ask them to check the dog's blood sugar.