I've been using an e-reader for a couple years now since my eyes started giving me trouble and and let me tell you, the ability to crank up the font size has been a game changer. No more squinting at tiny print. And that backlight? You can tweak it so it's not blasting your eyes, especially nice in low light.
Out on the porch, the screen doesn't glare like some tablets do, which is perfect for sunny days. I keep mine under 150 bucks, and it's held up well. Works great for folks our age.
Just play around with the settings when you get one, and you'll find what suits your vision best.