Re: teaching the blind
I think that a student, if he was willing to do so, could be assigned to assist the blind student during class. That way Sempai and Sensei don't have to continually take time aside to coach the blind student themselves, which could detract from the lesson the rest of the class is receiving. We did that with the deaf guy in our dojo years ago. It's also the same thing we did with most new people. You pair them up with another student, not just to practice techniques, but so that student can sort of instruct them on the nuances of dojo training. In the case of a blind person, they'd always be paired with someone in order to insure that the blind person is safe and doing things properly.
I do think that a blind person should be able to train if they really want to AND if the dojo personel agree to allow them too. However, we can realistically say that their training would need to be different, or augmented to a degree. Maybe a little slower and more hands on. And that's fine, but that extra attention shouldn't detract from the quality and intensity of training that all the other students are paying to receive. It's all about trying to be acommodating to everyone in the dojo.