[BuckyBeaver]

It's because paper doesn't EMIT light; it only reflects it. This simple fact was ignored for the last 30+ years of OS vendors pushing inverse color schemes on us. I see it as a vestige of the "desktop publishing" fad of the late '80s/early '90s, which sought to make the computer screen an analogy for a piece of paper. Or Apple's attempt to look "different."

Now all of a sudden people finally realized that reading dark text off the surface of a glaring light bulb all day is a shitty way to work, and vendors have backpedaled clumsily to offering a hard-coded "dark mode." But we already had an even-better solution: Windows let users set up their own system-wide color scheme, from Windows 3.1 through XP or even Vista. Any properly-constructed application would inherit the system colors for various on-screen elements and guarantee legibility. If you wanted to change the look of all your applications, you had one central place to do it. And if, as a developer, you wanted to guarantee a color scheme, all you had to do was make sure you overrode both foreground and background colors.

But Microsoft actually REMOVED that capability just in time for it to become desirable to more people than ever. Brilliant.

[orbital-decay]

>It's because paper doesn't EMIT light; it only reflects it.

What's the difference? I've seen it repeated over and over and it never made any sense. If your screen is too bright compared to the environment, turn it down. The only practical difference seems to be uniformity - screens are much more uniform. No shadows, no dependency on the angle to the light source etc. Which is... great?

[quesera]

The first things that springs to my mind is that the spectrum of emitted light from an active display is different from that of reflected sunlight/artificial light off of paper made from pulp/linen/cotton.

Active displays can be fatiguing for a variety of reasons, including brightness as you mention, but also the "unnatural" light spectrum.

Also, of course, blue light is believed to affect your circadian rhythm, so can cause disturbances after sundown. Most ebook readers have adjustments for this though.

[BuckyBeaver]

It's a good question. One thing is that the brightness of the page will always be appropriate for the ambient light, since it is determined by that light.

Beyond that, I'd speculate that screens don't retain as much contrast when you turn their brightness down, compared to physical materials presenting similar "brightness" under ambient light. But really that's just some talking out the ass with no research to back it up.