What's the point of Dark mode on an eink screen?

For some people it's less eye straining if they're reading at night, doesn't help for me personally, but it's a popular feature

Because most of the page is dark, with light only coming from the text, the total light emitted is much less. That makes it less annoying to my wife, when I'm reading before going to sleep.

Eink doesn't emit light.

this is the worst kind of pedantic engineer comment that seems to infest this site. they're obviously talking about the frontlight. dark mode reflects much much less light back at the user through the lightguide because the dark bg absorbs more of the light.

It wasn't obvious. My thought process was that they were equating ereaders with eink displays, and they had a non-eink ereader. To me, emitting light and reflecting light are completely different.

(I suppose I'm not supposed to feel complimented by the term 'engineer'? I'm not trained/experienced in any engineering discipline, not even software engineering.)

If you want pedantic ridiculousness, well, notice that I never said that the e-ink emits light. It does, however reflect light back from the device's frontlight. The device taken as a system most certainly emits light, but less so when in dark mode.

Very true. Sorry for misreading your comment.

I thought perhaps you had a non-eink ereader and were equating eink screens with ereaders. Apologies.

Many Kindles have backlights for night-time reading!

I think they're frontlights :-)

But indeed it's a feature I cherish.

I use dark mode for this too!

I have no idea but users seem to like it despite all the ghosting.

The reason I use koreader is because it can sync my progress on disparate devices. I have a normal sized kobo and also a phone sized viwoods eink device.