Report: 'Dark Mode' Effects Limited in Real Life

So-called video display "dark modes" on mobile devices may use more energy than ordinary display modes according to new research. The effect of the modes on human behavior may be counterproductive.

The claim comes from BBC Research & Development, a technical and engineering group within a British broadcaster that's previously developed technologies such as digital radio and over-the-air television broadcasts. It's running a project to test whether advice for building low-energy apps and websites is actually effective.

They were looking into a format known officially as a "light-on-dark color scheme," but more commonly as "dark mode." That's where the usual format of dark text and icons on a white background is reversed to be predominately light text on a black or other dark background.

Brightness Settings Adjusted

One of the key arguments for using such a mode is to reduce power consumption (another is to help reduce brightness-induced eye strain in a dark environment). One claim suggests that a Google Pixel uses six times as much power to display a purely white screen than a purely black one.

Other studies, which concentrated on actual displays rather than a pure block of color, found power use cut by 42 and 63 percent respectively. That's still significant with mobile devices where screen displays can be one of the most common sources of battery drain. (Source: bmmagazine.co.uk)

The BBC R&D study looked into whether these benefits actually exist in real-world use rather than lab tests. They asked test participants to adjust a device's brightness on a given website until they were comfortable viewing it. Each participant did the same exercise in both normal and dark mode.

They found that 80 percent of participants turned the brightness up much higher in dark mode, to the point that it wiped out the theoretical energy savings. They described this as a "rebound effect." (Source: bbc.co.uk)

Sleep Effects Also an Issue

This is only one aspect of dark mode, however, with some users preferring to use dark mode at night rather than as a permanent setting. Indeed, many devices can automatically switch to dark mode at sunset.

One theory is that light text on a dark background offers greater contrast that improves reading in low-light conditions. Another is that emitting less light inherently reduces the "blue light" from screens that's associated with making it harder to get to sleep shortly afterwards.

Does Dark Mode Really Reduce Eye Strain?

Many proponents of dark mode claim it helps alleviate eye strain, but scientific research on the topic is mixed. While a lower brightness setting can be easier on the eyes in dim lighting, the contrast of white text on black backgrounds may lead to halation (a visual distortion effect), making it harder for some users to read text efficiently.

Studies have also suggested that prolonged reading in dark mode can cause "screen blur," where users perceive more strain as their eyes work harder to adjust between text and background. Those with astigmatism may find dark mode particularly difficult to use for extended periods.

Dark Mode and OLED Displays

One area where dark mode is beneficial is on OLED (Organic Light Emitting Diode) displays, where each pixel emits its own light. Unlike LCDs, where a backlight is always on, OLED screens can turn off individual pixels to create true blacks, theoretically saving energy in dark mode.

However, studies show that the savings are most noticeable at high brightness levels with predominantly black content. If users compensate by increasing brightness due to perceived dimness, the overall benefits diminish.

Dark Mode and User Productivity

Another dimension to the debate is how dark mode impacts productivity. Some users report increased focus and reduced distractions when using dark mode, while others find that prolonged use strains their eyes or makes text harder to read.

Developers, designers, and programmers often prefer dark mode, as they claim it reduces glare from white screens. However, not all work environments benefit from it equally, and usability testing remains crucial in determining whether dark mode truly improves efficiency for the average user.

Dark Mode Adoption Trends

Dark mode has gained widespread adoption in operating systems, applications, and websites over the last few years. Major companies like Apple, Google, and Microsoft have integrated dark mode into their systems, citing user demand and potential energy savings.

However, user adoption is not universal. Some users stick with traditional light mode due to readability concerns, while others toggle between modes based on ambient lighting conditions. With companies continuing to refine their implementations, the debate over dark mode’s true benefits is likely to continue.

Developer Considerations

App developers and web designers have increasingly been offering dark mode options, either as a setting or through automatic adjustments based on system preferences. However, the debate over its actual advantages suggests developers may need to rethink how they implement these features.

Instead of simply reversing colors, developers might consider hybrid approaches, such as softer grays instead of pure black backgrounds, to reduce contrast strain while still cutting down on light emission.

What's Your Opinion?

Do you use dark mode on your devices? Is energy consumption a factor in that choice? Should we do more research into whether energy-saving settings actually work as described?