the biggest change for my sleep was switching to an e-ink device with front lighting. Phone screens always left me wired. The way those front-lit e-readers work is by casting light across the surface of the screen, not blasting it straight into your eyes from behind the text. It feels more like a book under a gentle lamp, no glare, no harsh blue tones if you adjust it right. I can read for hours without that gritty, strained feeling.
Some models even have a warmth slider now, which is a game-changer for pre-bed reading. It’s not about brightness, it's about the quality of the light. A traditional tablet backlight just floods the display, but e-reader lighting seems to work with the paper-like surface. My old Kindle Paperwhite basically cured my late-night headache habit.