Backdoc - Some people might not even think this for your dad... but I did this with my grandfather in his 80s with macular degeneration as well and he had a blast.

Helicopter ride with the dog sledding.

Although he couldn't see much from the helicopter, just being in it as well as stepping onto the glacier, getting to sit in a sled that the dog was pulling, as well as getting to meet/pet the dogs - that was one of his favorite things. It's very "Alaska". No one imagined he'd have such a great time with it (We booked it because of others on the trip) but it was one of his favorites and I'd recommend it to others who might not have the sight.