Dark mode if your screen brightness is way too high. Light mode if it isn't.

day → light mode ⇒ less eye strain

night → dark mode with high brightness ⇒ less eye strain

Gray Mode, obviously. /s

Seriously, the best UIs let users adjust things to their preferences instead of forcing one or two-polar-opposite choices.

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.

Staring into a light source that contrasts enough with the ambient light to contract my pupils is uncomfortable. I don't want to do that even if it makes me read faster.

led dark, eink light

I like light mode with lower screen brightness.

Dark mode on all LED screens, with blue light filter, at low brightness.

Dark mode at high brightness and light mode at any brightness on LED screens both give me migraines.

That said, light mode on non-emissive (e-ink, actual paper) is find.

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.

Dark mode after sunset, light mode after sunrise, obviously. Just as nature intended.

orange on black was it in the olden times (except on ASR-33s. q.v. https://www.eetimes.com/feast-your-eyes-on-my-asr-33-teletyp...)

Light mode forever

After several lifetimes of intentionally exposing myself to black/colored text on white, I switched to dark mode last week and haven't looked back.

With such an extensive time study, highly unlikely to be usurped any time soon, and the result being quite the opposite of what I set out to prove, we can all safely put this debate to rest.

A contributing factor is my keratoconus has had some kind of remission. Which is a good thing. At one point I had so many focal points in both eyes, without corrective lenses and before surgery, more than a dozen overlapping versions of text produced unreadable spaghetti. Unless it was a very tiny font from a distance, and then the glyphs only partially occluded each other, and I could I decode them.

Looking at one of those small bright electronics power LED dots across a dark room, I could clearly see all my focal points in each, and focal webs meadering between them.

So I feel quite privileged to be able to use dark mode with unaided eyes now.

why doesn't HN have a dark mode feature?