The theory is cool, but the ending is the practical part - there are system APIs to tell you which one the user prefers, so you can just make users happy and provide both options.
The fundamental mechanism seems to be that light mode causes pupils to contract by exposing the eye to more light. This decreases spherical aberration and increases depth of field just as using as smaller aperture on a camera lens does.<p>Staring into a light source that contrasts enough with the ambient light to contract my pupils is <i>uncomfortable</i>. I don't want to do that even if it makes me read faster.
orange on black was it in the olden times (except on ASR-33s. q.v. <a href="https://www.eetimes.com/feast-your-eyes-on-my-asr-33-teletype-terminal/" rel="nofollow">https://www.eetimes.com/feast-your-eyes-on-my-asr-33-teletyp...</a>)
I like light mode with lower screen brightness.
Dark mode after sunset, light mode after sunrise, obviously. Just as nature intended.
Light mode forever
Dark mode on all LED screens, with blue light filter, at low brightness.<p>Dark mode at high brightness and light mode at any brightness on LED screens both give me migraines.<p>That said, light mode on non-emissive (e-ink, actual paper) is find.
day → light mode ⇒ less eye strain<p>night → dark mode with high brightness ⇒ less eye strain
led dark, eink light
Gray Mode, obviously. /s<p>Seriously, the best UIs let users adjust things to their preferences instead of forcing one or two-polar-opposite choices.
Dark mode if your screen brightness is way too high. Light mode if it isn't.