E-ink displays are functionally equivalent to paper. You won't get a headache from reading them; they aren't backlit. You really ought to try one before you make up your mind, you know; what is the worst that can happen? It's not like they put mind control chips in the things.

Look, if you've tried one out for a while and it's not your thing, that's cool. But your reasons are the same ones I used before I used an ereader, so I'm suspicious of your familiarity with them.