Research data says that reducing eye strain when using a dark theme does not occur in most situations.

A little earlier, I published a translation of the article “Dark Times are Coming,” the author of which declared the benefits of the regime and prophesied its widespread introduction. This article focuses on research on the topic and the effect of the option on different people. - approx. trans.

Night veils the screens of our computers.

It comes in the form of a dark mode, fashionable in the technology industry function, when the usual bright backgrounds are replaced with dark blue or black. Twitter released a dark mode for the site in 2017, and Facebook Messenger introduced a similar feature in April 2019. Apple's announcement at WWDC last week was particularly noteworthy, as iOS 13 coming out in the fall will also receive a similar option. The company claims that with the dark mode, “every element on the screen will strain eyes a little less,” and some people claim that turning on the function helps fight migraines .

But there is practically no scientific evidence to support such statements. Even for users with vision problems, the dark mode is not necessarily better than some of the known alternatives, but, again, there is very little research on this.

One thing is certain: for many people, for the most part of the day, a dark regime does not raise productivity or reduce eye strain. At best, it's probably just an aesthetic option.

On the contrary, dark modes can reduce readability and performance for most people. The 2003 study looked at how different display settings, including negative polarity (light text on a black background) and positive polarity (black text on a white background), influenced user performance. It turned out that it was easier for the subjects to perform tasks with positive polarity.

Another study conducted in 2013 examined the effects of positive and negative polarity on both young and old people, since theoretically the deterioration of their vision could affect their perception of brightness and contrast. Both age groups, as shown by the results, coped better with the tasks with a white background.

Although black text on a white background may be even better for productivity, dark mode connoisseurs have their own serious argument: this function can be useful at night.

Just as when we look at a bright light bulb on a black background or try to look at a dim corridor from a brightly lit room, if the screen of the phone is much brighter or dimmer than the surrounding space, it will be difficult for the eye to adjust. This effect is familiar to anyone who has ever squinted, checking the phone at dusk, or trying, while in a brightly lit room, to look at a dark television image. In such situations, according to the Mayo Clinic, the eyes are prone to exertion, and symptoms include dry eyes, fatigue and headache. True, in the long run, there should be no serious harm to health.

Evidence of the absence of serious harm to health is available on the Mayo Clinic's website : “Eye strain (eyestrain) does not lead to serious long-term consequences, although it can be annoying and unpleasant. It can lead to fatigue and reduce concentration. ”- approx. trans.

Many models of smartphones and computers and so equipped with ambient light sensors, adjusting the brightness of the screen under environmental conditions. However, for people who are particularly sensitive to light or just for those who do not like Apple’s night mode, the option to turn on dark mode can be a nice addition.

“Dark mode can be very useful for brightness-sensitive people as it reduces the overall screen intensity,” says Loren Milne, an associate professor of computer science at Macalester College, whose research focuses on accessibility issues. "Many people with poor eyesight, and especially people with tunnel eyesight, prefer white text on a black background, since it is easier for them to distinguish words." Although operating systems have long allowed the inclusion of color inversion, it can lead to the Andy Warhol effect, which is not always desirable or pleasant.

However, according to Syed Bill, a Ph.D. in computer science at Stony Brook University, a dark mode may not be as effective as inversion. In his study of available technology for people with visual impairment, he found that users with certain diseases, such as glaucoma, prefer large text in high-contrast modes. In such modes, the text appears yellow, white or green on a black background. “It's not at all like the Mac's dark mode,” he says — the dark mode uses different shades of gray, the borders [and] edges are not very noticeable [or] distinct, and the mode just doesn't work for non-native applications. ”

Thus, while a dark regime, for example, on Twitter can be aesthetically pleasing for people with normal vision, it is quite likely that it is simply not the right option for people who really need accessibility. This does not mean that the dark regime is harmful - it just does not help people with visual impairments.

Remember, however, that quite a bit of research on modern dark modes goes beyond affecting readability for users with normal vision. Presumably, properly made dark modes can help people with photophobia (photosensitivity) or some other visual impairment. That's just because of the lack of information on this topic is difficult to understand how much they can help and how exactly they are best implemented.

“We really need more good, modern research,” says Silas Brown, a partially blind scientist from the University of Cambridge. People with brain damage that can affect the processing of visual information, such as dyslexia, migraine, and autism, can react differently to different combinations of colors and brightness, but “all of these states are poorly understood, each of them, in fact, is a generalization for a number of states, so we cannot say whether the screen settings will help everyone”

However, Brown and Milne agree that having options is better than not having them, and some people may find that the dark mode helps them. “I’m always happy when [the developer] officially adds options such as the dark mode,” says Brown, which gives everyone the opportunity to check whether the effect is personal for him. ”

It is commendable that Apple and other companies offer the opportunity to use the dark mode, only use it when it's bright around, probably not worth it. And since many people look at the screens during the day and sometimes at night, more research is needed on this topic. Now our knowledge is full of gaps. This is especially important for people with visual impairment or headaches. Dark mode is better than nothing, but the potential for improving accessibility is much broader if corporations once decide to make it a priority.