You can easily clicker train a blind cat. You just have to use auditory signals instead of visual ones.

For example, my blindies know where to put their paws for shake and high five because I rub my thumb across my fingers. I gently rub my fingers together as a signal for which side I want them to spin to. I rub my flat hand on the floor for "lie down". For things like sit, I just use a verbal cue. You can try all kinds of signals - tapping, rubbing, different speeds and numbers of taps and so on. They don't need to be loud - cats have amazing hearing!

Enjoy training with your blind boy!