[jakub_g]

Many good advice in this thread already. Personally I'm doing ok with good warm lighting in the room, low brightness/contrast (~60/30 during the day, ~50/25 in the evening), and I activate "night light" mode of Windows once it gets dark; window on the side, take breaks from time to time and use cold water to refresh your face. I wear glasses and as other say, I zoom in the text a lot. Big text makes things quick to read and hence less eyestrain.

Whether to use dark mode or light mode in text editors/websites depends on the lighting condition around you. I mostly used dark mode now (except GitHub), but I make sure the contrast of the theme is not too big, not too small. But in my prev job we had white room with white everything and lots of light, and I was much more comfy with light themed terminal (although not white; soft bgcolor like HN has).

On top of that I will add that for some reason for me, mobile usage contributes way more to eyestrain/headache/fatigue than computer use (order of magnitude diff). I can work all day long on a laptop without much issue. But checking mobile, especially as first thing in the morning or in late evening (even in blue light reduction mode), makes me much more tired nearly immediately for some reason.