It's not even about preferences for me. I can spend all day in light mode without eyestrain, without issue, very comfortably.

If I encounter a page that's dark mode (GUI), after about a minute or so, I start seeing spots before my eyes that stay with me for quite a while.

To wit... I use these two firefox extensions to convert pages from Dark Mode to Light mode. If one fails, the other usually finds success (I think they work in reverse too):

https://addons.mozilla.org/en-US/firefox/addon/site-color-ch...

https://addons.mozilla.org/en-US/firefox/addon/no-color/

side note: I cannot explain why the terminal (FG/White; BG/Black) feels incredibly comfortable to my eyes. Maybe it's the larger font I use (80 columns = ~2/3rds of my 16" screen width), the right amount of contrast, the fixed spacing...?