It is pretty subjective feeling IMO.
When the first iPad came out, its backlight was very strong even with the brightness level on the very minimum, so, I used to read at night using yellow sunglasses until I found pdf app that was really capable of reducing the brightness completely, instead of just faking it by using darker colors.
Anti Glare Eyeglasses, Anti Blue Rays, Computer Reading Glasses (Black, Yellow Tinted Lenses)
https://www.amazon.com/gp/product/B0...=mr060-20&th=1