Pretty much anytime I have to read some white or light grey text on a dark background it is punishing on my eyes and I end up with light-lines in my vision temporarily after. I’ve given up on entire websites because they only have a dark theme and the simplified read mode doesnt work. On occasion, when I really needed to read a lot of text from somewhere I will copy and paste into a word processor. Light mode, or anything with dark text on light background, doesn’t strain my eyes nearly so much.