PuzzleSight offers online puzzlegames, especially developed for the badly sighted and the blind. Where there's too few products for this visually challenged user group, it's a tough job to pull off - try using any digital device without looking. I've been involved in product development and UX, I'll present three concepts.
1 universal key commands
PuzzleSight is visited on desktop and tablet devices. When it comes to user interaction, these people cannot see the screen (well enough). Enter speech. The voice-assistant-system will read anything you want. That's the easy part. Since you cannot talk to your computer and you cannot use your mouse (you can't see it move) - you need dedicated keys. Keys you get to remember so that you think less and less about them - so you get to puzzle. Regardsless on what device you happen to be.
Tabletscreens offered an extra challenge when it came to text input for crossword puzzles. Upon entering text, the touch-keyboard appears - covering most of the screen. Now you can't see anything. So I designed an inputwheel. It's a local keyboard, enabling you to choose letters without drastically moving your finger. Without covering anything, really.
Sudoku is a puzzle demanding you not to simply see, but to study, to stare at it. Going through rows, columns and matrices you try to discover the missing numbers. Not being able to see all this cannot be solved by getting them read aloud. It's too much information - if you're even able to do it, you wouldn't call it "fun". Still I found a way.