The just released MS-5 from Behringer ( thread ) looks just the sort of interface for anyone with visual challenges.
There are NO screens, and NO modes on the controls. You’d be able to feel and hear the positions of all the controls, with perhaps some small modification to things like control knobs with pointers and that sort of thing. Maybe some raised bumps, or even braille too at strategic places, like on the multi-position routing switches along the top.
There is a lot of controls, but that’s also an upside too, there are a lot of control options once you get the feel.
No presets, but there again that can be an upside.
Oh and it’s affordable.