I'm absurdly nearsighted (not safe to drive with the best perscription available) and -for myself- this isn't a reason to CTB. If I couldn't function on my own because it gets worse, then it might be a reason -for me.
I've dealt with insomnia (nightmare driven) for at least a decade now. Again -for me- it wasn't a reason, in and of itself.
That said, the reason that I'm going to be CTB soon is because of what supposed MH "professionals" systemically did to me, supposed "treatments" that only made my situation worse and worse and worse, until a specific pivot point (for the full and detailed account read
https://wrenbriar.gitlab.io/) I've woken up with nightmares related to that specific pivot point almost every single day since (and there was a really weird medical situation that led me to not sleep enough to hit REM for almost a month, and then I was declared braindead for 2.5 days; discounting that medical situations, I've been woken up by the nightmares
every single day since). While I wouldn't CTB because of the nightmares, I am CTB because of the pivot point event and every single one of those nightmares remind me of exactly why I now longer fit in this f'd up world!