I am old enough to have written programs when "dark mode" was the default (black background and green or amber text, 40 columns, 80 columns if you were lucky), and I can tell you that light mode is much easier on my eyes.
Black text (real black, not this fancy grey web designers seem to prefer) and white background on a properly adjusted monitor where the white doesn't blind you is my go-to since monitors became good enough to make it possible.
By contrast, I am old enough to have written programs when "dark mode" was the default (black background and green or amber text, 40 columns, 80 columns if you were lucky), and I can tell you that dark mode is much easier on my eyes.
”... we strongly recommend that designers allow users to switch to dark mode if they want to — for three reasons: (1) there may be long-term effects associated with light mode; (2) some people with visual impairments will do better with dark mode; and (3) some users simply like dark mode better.”
And from a StackOverflow discussion:
Visual fatigue research: Unfortunately I could not find very much research which measured computer screen visual fatigue in comparison to black-on-white text as opposed to white-on-black. The only piece I could find was a short reference in "Reading text from computer screens" by Mills and Weldon (1987) from the journal ACM Computing Surveys. Section 4.1 of that paper, titled "polarity", goes over important works at the time, including this piece:
”In contrast to the results in these studies, Cushman [1986] found that subjects who read continuous text from positive contrast (light character) VDTs reported less visual fatigue (as measured on a subjective rating scale) than those who read from negative contrast (dark character) VDTs.”
I mean, parent post said "easier on my eyes" and "ymmv". It doesn't take much convincing for me to believe that light mode is easier on parents eyes and dark mode is easier on your eyes. I believe you.
Black text (real black, not this fancy grey web designers seem to prefer) and white background on a properly adjusted monitor where the white doesn't blind you is my go-to since monitors became good enough to make it possible.
YMMV, of course.