Okay back from work. I would argue anyone saying not to get the GAC card. What it also does for blind is give you front row on rides also, so there is no obstructions in your way that would make your ride less enjoyable.
What most people do not understand is that blind individuals usually have some sight, so you are entitled to a GAC card that fits your need.
And I am sure you do not want to take advantage but just want what would be more enjoyable. In the old days when disability got you front of the line, I missed a lot at DL, now I make sure I do not ever miss a thing and the pass helps with that, and I would tell you not to get a pass for front of line because you would be missing a lot that he would enjoy, so I never use the exits anymore.
He will love INDY and RR, both of these lines have lots of tactile sensory. Even if he is to little for INDY ask if he can walk the line to feel the stone gravings, there use to be water that trinkles down which was neat to feel over the cuttings in the stones, the bamboo rails and the sounds it makes when you tap on them, the ropes, the well these are all great to explore. In RR the walls and the shapes engraved into the walkway. All of toon town is like that. I personally hate these rides, not the best when you are blind to be pushed and spun in many directions but the lines are the best.
Stop and feel some of the trees, bushes and flowers, most of the time the CM's will let you, since they will see he is blind. Yes, ask to feel not only mickey and minnie but other charactors as well. Make sure if you go to any of the dining where they take pictures to include the dog, they will allow this.
This may sound weird but let him experience with feeling the ground barefoot, or with his hands. I love the pad outside SM, where the kids run through water, it feels so cool on your feet. But the walk around DCA is neat also. The board walk at Ariel's Grotto feels neat barefoot, and over where the tug boat is and where the bear challange is. I always take my shoes off and walk these at least once a trip.
I like to feel the plants in DCA near the chew chew train. Lots of plants there to touch and feel.
I think many have made suggestions about the smells.
But if he has any sight at all please ask for a GAC pass and don't feel you do not have a right to one. Many people on this sight feel strongly because it was abused in the past and I have heard over and over again that blind people do not need a GAC pass, yes you do and you are entitled to it. It does not give you any rights to line jumping, but once you are at the front of the line if you have the pass and the CM knows what it means, (which they are getting much better at, since last Feb most of the CM did know what the card meant, and they do not see it very often. But it will get you front row seats at Alladin, on rides like Indy, SM and Splash just to name a few, of course you can always say no and sit elsewhere if you want. Since I have some sight up to 5 feet and I have colors that I can see, seeing space mountain from the front is nice, otherwise I would not enjoy it as much, same with alladin and the parades, it may only look like a kalidoscope but why if that is all the enjoyment I can see should I miss it because someone who believes w/c are a necessity if you have a disability. Not to get down on those who try to help all disabled but I hear so often on this sight that blindness does not give you a pass and it does and it is great for those who have even a little tiny bit of sight, which 95% of all blind people have something.
I hope you have a wonderful trip.