Before you casually dismiss it as a worthless idea, consider that some victims have fewer capabilities than Bauby was left with.

If a person has lost all capability such that they cannot even blink or move their eyes, I’m not sure what else they could do to communicate. Breathing?

I don’t think the idea is worthless, just not worth as much as what others may think.

I'd genuinely want to be euthanised in this situation. But that's a whole other debate.

I believe this already exists - an eye tracking camera that lets you indicate which letter you want next, with some predictive text capability. Can't find the exact video now, though.

The market leading system is made by Tobii Dynavox.

https://www.tobiidynavox.com/about/about-us/how-eye-tracking...