“Perceptual disability” would exclude people with physical disabilities who are unable to physically handle a book, with ALS, for instance, and other neurological diseases that would be a barrier. I don't think we've had a chance to really decide whether “perceptual disability” or “print disability” would be the language of choice, but what we would strongly advocate for, and my colleague will correct me if I am wrong on this, is that the language must be inclusive.
It must be inclusive of anyone with a disability that, for whatever reason, due to a disability that is physical, perceptual or cognitive, which is the same thing, bars them from being able to visit the bookstore and buy a book.