OK, take two. I launched this with only two options and got (justifiably) yelled at. I thought that Dark was going to win going away, but apparently it's close enough to be interesting. So, please boost and let’s take a wider sample.
Light Mode
19.1%
Dark Mode
41.7%
Both, it depends
39.2%
Poll ended at .
@timbray For old eyes, dark mode is significantly harder to read due to blooming. In light mode, or as we call it, paper, the bleeding is much less noticeable.
@robpike @timbray Ah so maybe that's why I prefer light backgrounds and all the hip youngsters go for dark: it's an age thing!
@lexiconista @timbray I truly believe it's an optics thing. Old eyes scatter more light, which smears white letters on black more than the other way around, because in light mode the scattering is on areas already white.

@robpike @lexiconista @timbray

Beyond old eyes, scattering light, tired eyes also do it... As my eyes get older, I find that I can't read dark mode nearly as well at the end of the day as I can the beginning of the day.

This is all making me reconsider using dark mode for an editor at all!