The Dark Side of Dark Mode

In the late 70s when the University bought new monitors, the student lab switched to dark mode. I noticed right away that nearly every monitor had reflections from the room lighting making them hard to read. On white monitors, it made no difference.

I use night mode when reading in dim light or darkness on Kindle.

As I said, there are always outliers. I wrote the article because Apple is claiming that Dark mode is somehow better and people are switching to it because it has the Apple seal of approval. But when something is literally the major feature in a macOS release, I believe it should have some actual science behind it, not 40 years of research showing that it will make most users slower and less productive.

I am curious though. You say that you could not do your job if you had to stare at a white screen all day. Assuming that you’ve been working with computers for more than a year, how did you do your job before the advent of Dark mode?

@charles4 can likely answer this. I suspect what @godofbiscuits was getting at is that paper will reflect the color of light being shown on it, so if you’re reading a book illuminated by a rather blue LED light, that will probably be pretty similar to reading a screen emanating a similarly blue LED light.

Curtis Wilcox

    June 1

I think what most people don’t realize vs. paper is that reading paper by an LED light source isn’t different to reading from an LED backlit screen. It’s still LED light that’s being conveyed into your eyes and onto your retinas.

Citation please. I expect there are many differences between light that passes through liquid crystal and multiple filters including the red, green, and blue ones creating each pixel and light that is partially reflected and diffused by paper or any other surface.

I don’t know what LED lamps vs. backlights have to do with Dark Mode.

I agree 100%. And if I remember correctly, most LED screens don’t actually emit pure white light. There are different combinations of RGB groupings manufacturers use to solve this problem. From what I heard from some IT people I worked with, getting a bunch of LED screens calibrated for production groups is a big PITA.

Before dark mode, I used inverted colors, dark mode browser extensions, and dark color schemes in any apps that would let you customize the colors.

Actually, I still use all these features…

We’re talking about several different things here and probably conflating things that should be viewed separately. Adam’s concern looks to be that Apple is overhyping Dark Mode and I can understand that. However, I don’t want people with normally functioning eyes to pile on to the idea that Dark Mode is a bad thing. I’ve fought with a genetic eye disease for 76 years now, and I find that Dark Mode helps me to use my Mac a great deal.

I’m a scientist myself and I think that the research that is cited here is likely pretty well done, but before using it it to condemn a feature that you don’t need to use, please consider that there are people who find the feature very useful and life changing. As I’ve grown older, I’ve come to realize that we are often more different from each other than I’d ever imagined, though not unworkably so. So go ahead and offer your comments from your viewpoint, but please don’t assume that because it works for you, that it works the same for everyone.



That’s really the key fact, and thanks for noticing. When Apple promotes a feature like this, people assume there’s a good reason for it, and in this case, 40 years of research shows that it isn’t for most people, most of the time. Obviously, everyone is free to choose, as in so many other things in life, but they should also know what science says about the choice.

I found myself using dark mode more and more, and just the day before Adam published his article I finally had an epiphany that I was actually having eye trouble causing a bloom around bright lights (likely a posterior capsular opacification) and made an appointment with my ophthalmologist. In the last few days, it has progressed to the point where it’s obvious, and dark mode is now a necessity for me, to the point where I’ve even made some Javascript bookmarks to force some web sites to use darker backgrounds. (The condition is probably easily corrected with laser surgery, so my need for dark mode is temporary.)

I remember being kind of frustrated by a lot of what seemed conflicting or just plain wrong advice in the field of ergonomics, until I encountered the aphorism “the best position is the next position.” That is, the goal of ergonomic design shouldn’t be to find the one perfect position, but to strive for a setup that allows for movement and change. I see dark mode in a similar light (ugh, sorry). It’s an option for when you just need a change or to accommodate specific conditions.

I have to agree, though, that making it the flagship feature of a major release seems excessive.



Much the article and discussion is as though everything in Dark Mode was white text on black, which isn’t the case. In many app the menus are dark mode but the content is light mode or there is an option. I like how this separates the menu stuff from the content.
The one app I am not happy with is Calendar in dark mode. Doesn’t work for me and there is no option, (except BusyCal which I use instead).

I suspect a big reason Apple is making such a big deal about Dark Mode is that the big majority of people currently in the market for a computer don’t know what it is and might think it’s one of many cool features that makes shelling out the extra $$$$ you spend for a Mac justifiable. They are getting a lot of favorable press about it, especially in the general consumer market.

Light contains no colours, light is electromagnetic energy at a combination of wavelengths. Light bangs into receptors inside the eye. Those receptors react by emitting neurochemical pulses that travel to the brain. The brain perceives certain patterns of those pulses as colours. No colour exists before this point.

An incandescent source of light–the sun, a candle, an Edison lamp–all generate a continuum of wavelengths, which vary predictably with the temperature of the source. The curve of these wavelengths forms a lamp’s “colour temperature.” It can be used to measure the temperature of a remote light source. In contrast, fluorescent lamps, LEDs, and LCDs all generate discrete wavelengths, not a continuum

The colour-sensing receptors in the eye (cones) contain pigments that bias their sensitivity toward different wavelengths. If individual wavelengths strike the cones–if the light is not incandescent–then the cones will not react predictably and the colours we see will not be predictable. This holds no matter whether the LED is pouring light from a display or is illuminating a sheet of paper.

“Unpredictable” is the key word here. There are no standards for assessing the colour of flourescent lamps, LEDs, and LCDs. You can hold a colour-temperature meter up to an LED and get a reading, but since the LED is not incandescent, it has no colour temperature for the meter to read, so the numbers are meaningless. The “colour temperatures” advertised for these lamps are not technical specifications, they are marketing descriptors no more meaningful than “warmer” and “cooler”, and those numbers are no more comparable from one manufacturer to another than the adjectives would be. Moreover, the numbers provide no information whatsoever about how closely the lamp looks compared to an incandescent source that actually reaches the temperature.

Since eyes vary and preferences vary, one size probably fits none. That said, I suspect dark mode on a computer is roughly comparable to a size 12 or 13 shoe.

Okay, “incandescence” is light produced by heating matter and the term “color temperature” is called that because the wavelengths of visible EM radiation produced correlate to how hot the matter is. “Luminescence” is light not produced by heating matter, fluorescent lamps, LEDs, lasers, and fireflies are all examples. Why is the color temperature meter’s reading of a luminescent light source meaningless? It’s clearly meaningless if your purpose is determining how hot the light source is but why is it not meaningful for the purpose of knowing something about the light emitted? Why should I not believe my lying eyes if an LED lamp looks like a particular temperature incandescent lamp?

Manufacturers try to make LED lamps look incandescent, and sometimes they succeed, but the reading on a colour-temperature meter does not predict this.

That’s because you cannot describe an entire spectrum with a single figure.

If the spectrum of a set of LEDs approaches that of sunlight, the lighting (at least in terms of color) will be next to indistinguishable from incandescent bulbs.

I’ve updated the article to clarify a few points that people were tripping over and to acknowledge some additional situations in which Dark Mode is useful. And to focus on the fact that I’m mostly criticizing Apple for promoting Dark Mode heavily despite the science saying that it will likely hurt productivity for most people, most of the time. We need Apple helping us be more productive, not less.

I am 83 years old and have vision problems. I tried Dark Mode for about 3 days to see what all the fuss was about. I too found that I was straining to see things that I normally see perfectly in normal mode, so I switched back.
I also bitterly resent Apple having switched off the color icons in the Finder sidebar and in the menubar, as these were of great assistance to me in quickly executing my tasks of the day of which there are many. I was able to use XtraFinder to restore the color and choice of icons to the Finder sidebar, but I still have trouble with the black menubar icons I have to resort to during the day. Why did Apple have to force independent developers to turn their heretofore easily identifiable menubar icons into blobs of black dirt? I resent the extra strain it has added to my hours each day on my MacBookPro.

There are rumors that some color will come back to the sidebar in macOS 10.15, due to be announced on Monday. Fingers crossed!

Adam, I read your article yesterday, and then read some of the National Geographic magazine (May issue) shortly thereafter. The magazine had a sidebar with white-on-black text with a smaller face than the main story. There was no way I could read it without a magnifying glass. It was one of those coincidences of timing that occur occasionally, where I read something (your article) and then saw a demonstration almost immediately afterward that emphasized what I had just read.


Fortunately there are other measures available though they aren’t perfect: CRI, Color Rendering Index (how close the spectrum comes to natural sunlight) and CCT, Correlated Color Temperature (the human-perceived temperature, which generally varies with viewing conditions).

It’s possible that CCT is what an LED room bulb states without explicitly calling it CCT.

CRI is almost always reported for LED lights used for photography, and sometimes for mid to high end flashlights and high end room lighting. I haven’t seen any consumer LED bulbs provide it. For photography, 90 is now considered the minimum for normal use, though some situations may need higher. There are different ways to measure CRI, so for sensitive use cases you have to dig deeper.

This manufacture’s page shows illustrations of spectra for their 95 CRI LED compared to 80 CRI, halogen (which is incandescent) and fluorescent. Jump to the bottom three graphics:

If all the folders in the sidebar are essentially “a continuous color gradient” of the same color, then I fail to see the point when the goal should be near instant recognition. The examples shown attempt to make it into somewhat of a parlor game to stretch out the time needed to select the correct folder.
Why shouldn’t the user be able to designate the colors and icons to quickly distinguish one from the other?
Thanks to XtraFinder my sidebar is a mix of colorful icons alongside each folder’s name and/or thumb photos of each family member for whom a folder containing their info is named. But I shouldn’t have to use a kludge to do this - shouldn’t it be built into the MacOS?
My guess is that going to all-black non-descript organizational tools was simply a way to fake a non-operatrional speed increase in MacOS upgrades, or to cover up an actual speed decrease.