I watched Super 8, on I think Amazon, when it came out. I thought it was about the weirdest movie I'd ever seen, a narrated in real time action movie.

Come to find out, for whatever reason, it had audio description turned on by default.

As someone who can see and hear fine, I found it rather odd(before learning what it was). But for a vision impaired person, such a thing must be a game changer.