Juggling for Blind People

Putting aside that it seems to not work at all on my phone... how is a BLIND PERSON supposed to READ THE TEXT for how this works? This of course assumes blindness is binary (which I _personally_ know it is not).

I.. don't understand how this works at all. Why can't I ever catch it? Isn't it merely a matter of keeping the phone low?

Doesn't throw any balls for me.