| The idea that "nothing in the natural world has the contrast of a modern display" is backwards and keeps being repeated. The real world has far more contrast than any screen that can be manufactured. Think about standing outside on a sunny day. The sunlit pavement might be tens of thousands of times brighter than the shadow under a tree. Look up at a bright cloud and then glance into a shaded doorway. Your eyes can still make out detail in both. The dynamic range of the real world the ratio between the darkest and brightest things present at the same time is enormous. Cameras struggle with this. When you take a photo, the camera can't always capture both the bright sky and the dark ground correctly at the same time. Either the sky blows out to white or the shadows become black. That limitation is why HDR photography and exposure bracketing exists. Even modern digital cameras still capture a far wider range of brightness than most displays can show. That's why we use tone mappers in photography and video. Tone mapping compresses the huge brightness range captured by the camera so it can fit onto a display that only has a tiny slice of that range. So screens are not "more contrasty" than reality. They're the opposite. Displays are a bottleneck that force a very wide real world brightness range into something much smaller. Your eyes are also incredibly good at adapting. If you look at a white page of paper in sunlight and then look at black ink on it, the contrast between the two is extremely strong. Snow in sunlight next to a dark rock is another example. Nature is full of intense light and dark differences. When web developers avoid strong contrast because it feels "unnatural", they're misunderstanding the physics and the biology. High contrast between text and background isn't artificial at all. It's actually closer to how humans evolved to see clearly: dark shapes against bright surfaces or bright shapes against dark ones. The real ergonomic problem with screens usually isn't contrast between text and background. It's screen brightness relative to the environment. Many people run their monitors far brighter than the room around them. If a screen is glowing like a light source in a dim room, the whole display becomes visually harsh and fatiguing. In ergonomics, the usual advice is to match the screen's brightness to the surrounding lighting so the display feels like part of the environment rather than a flashlight in your face. When display brightness is set appropriately, strong text contrast simply improves legibility. The discomfort people blame on "too much contrast" is often just a monitor that's set far brighter than it should be. Reality itself contains vastly wider brightness differences than any display, so high contrast text isn't unnatural at all. It's a practical way to make information clear within the limited dynamic range that screens can actually show. |
Your points about day/shade contrast and eyes adjusting are correct, as are screen brightness levels people use.
> Look up at a bright cloud and then glance into a shaded doorway.
Yes, and that causes strain on the eyes. Our eyes very are good at adapting (as you said), but it is not pleasant to do rapidly or while trying to concentrate and interpret text.
Bleached white paper and black ink is (pretty generously) ~15:1 contrast ratio in a well lit room, which any half decent screen in the past 20 years surpass.
Pure black/white text is harder to read on screens since they are producing and pushing light at you (as opposed bouncing back ambient light like on paper). We have never seen text printed on paper at the contrast ratios a modern screen can produce, since there is no paper white enough or ink dark enough.
There are many things with typography that are finicky and sometimes counter-intuitive. Making text bigger and all-caps won't always make something more readable (see here: https://www.mentalfloss.com/transportation/roads/why-road-si...), likewise more contrast doesn't always make it more readable for everyone.
Of course there are people who require more contrast and larger type sizes and the great part about reading stuff on screens is we can often accommodate that better. Some websites/apps/etc handle accessibility options well and some really don't.
So I kind of went on a much longer thing than I wanted to... oh well. Sorry if I was too forthright in my initial comment, I guess clarity in intent/meaning can be just as important as readability.