Dark or white color theme is better for the eyes?

  • What is better for the eyes, a dark color theme or a white color theme?

    There are too many elements involved to be able to give you an accurate answer.

    It can't be answered without understanding the full context of the application, the users, the content, the functionality, the use cases, etc, etc.

    I'm curious, would the limitations of the display technology make a difference as well? Considerations include: How black is black, and how white is white? Do black pixels and white pixels get refreshed equally well? Is there more "bleeding" at the edge of a white pixel if the display is a light source rather than a reflective surface?

    Some people are light sensitive. They commonly have to take steps to reduce white point. Be it allergies, a migraine or just eye-strain in general working 4-8 hours a day on a bright site or app. Its ok when your room is bright and you need the contrast. Even in presentations with projectors, you absolutely need the contrast. Something more subtle like a book or newspaper is far easier on my eyes. There are devices out there though that just can't get low enough for me. I associate these with a tanning booth or lightbulb.

    Why was this question marked as a duplicate? It concerns programmers specifically, whereas the other question is more general.

    One aspect no one seems to have mentioned is that if your IDE is white-text on black background, every time you context switch to the browser or almost any other app, you are presented with black on white. That makes for a very straining contrast as your eye now has to contract the aperture to reduce the light coming in.

    I dumped dark colors for two reasons: they are inferior when the surrounding light is bright (daylight). In the night they're better, so you work in a console, but then you switch to a workspace with a browser, where website is mostly white and the amount of light burns your eyes. That's reason #2.

    Really the biggest issue in this Q&A is that there is a significant difference between display and other reading, as well as various reading situations (long vs short, distance vs near, font size, legibility vs readability) — the question setup is all just way too vague.

    I don't think that resolution in question: "This question already has answers here:" is correct. Resolution "This question probably has answers here also" is better. I remember this question without resolution mentioned above.

  • Hynes

    Hynes Correct answer

    7 years ago

    There has been a lot of research on this topic since the 1980s and a lot of it still holds true today. One study from the 1980s states this:

    However, most studies have shown that dark characters on a light background are superior to light characters on a dark background (when the refresh rate is fairly high). For example, Bauer and Cavonius (1980) found that participants were 26% more accurate in reading text when they read it with dark characters on a light background.

    Reference: Bauer, D., & Cavonius, C., R. (1980). Improving the legibility of visual display units through contrast reversal. In E. Grandjean, E. Vigliani (Eds.), Ergonomic Aspects of Visual Display Terminals (pp. 137-142). London: Taylor & Francis

    The reason why this matters is because of focus. As this article on UXMovement states, "white stimulates all three types of color sensitive visual receptors in the human eye in nearly equal amounts." It causes the eye to focus by tightening the iris. Since the eye is focused, dark letter forms on light backgrounds are easier to read. When using a dark background with strong light letter forms, the iris opens to allow more light in, but that causes letter forms to blur. Why?

    People with astigmatism (approximately 50% of the population) find it harder to read white text on black than black text on white. Part of this has to do with light levels: with a bright display (white background) the iris closes a bit more, decreasing the effect of the "deformed" lens; with a dark display (black background) the iris opens to receive more light and the deformation of the lens creates a much fuzzier focus at the eye.

    Jason Harrison – Post Doctoral Fellow, Imager Lab Manager – Sensory Perception and Interaction Research Group, University of British Columbia

    Now there seem to be varying factors into contrast and legibility. Room ambient lighting. Brightness of the monitor. Also you can mitigate the straining effects of white (#FFF) on black (#000) by simply lessening the contrast like using a light gray (#EEE, #DDD, #CCC) on a dark background (#111, #222).

    Update (Feb 7, 2020):

    A new article from the Nielsen Norman Group entitled, "Dark Mode vs. Light Mode: Which Is Better?", brings some more research to this topic. A couple key findings in the article:

    Cosima Piepenbrock and her colleagues at the Institut für Experimentelle Psychologie in Düsseldorf, Germany studied two groups of adults with normal (or corrected-to-normal) vision: young adults (18 to 33 years old) and older adults (60 to 85 years old). None of the participants suffered from any eye diseases (e.g., cataract).


    Their results showed that light mode won across all dimensions: irrespective of age, the positive contrast polarity was better for both visual-acuity tasks and for proofreading tasks. However, the difference between light mode and dark mode in the visual-acuity task was smaller for older adults than for younger adults — meaning that, although light mode was better for older adults, too, they did not benefit from it as much as younger adults, at least in the visual-acuity task.

    The research did find though that dark mode seemed to be beneficial for users with impaired vision:

    In Legge’s study, each of the 7 participants with cloudy ocular media had better reading rates with dark modes, whereas the rest of the participants, who had impaired central vision, were not affected by contrast polarity.

    Though they did note one caveat that this study used CRT displays instead of LEDs displays.

    A few takeaways from the article:

    1. In general, light mode leads to better performance most of the time for users with normal or corrected-to-normal vision.
    2. While light mode performs better, those gain seem to be more short-term. Long-term exposure may be result in myopia.
    3. Increased font-size in dark mode doesn't offset the gains from light-mode.
    4. Providing a dark mode though is still recommended though becomes of the potential long-term effects with light mode, some visual impairments perform better in dark mode, and some users simply prefer it.
    5. For applications which provide long-form reading (books, articles, even news sites), dark mode options are recommended.

    One other note with the studies cited in the article is that the studies focused on "glanceable" reading (i.e. reading 1-2 words on a mobile phone, smartwatch, or car dashboard).

    Further reading:

    One factor to consider which I don't see mentioned is that for applications which require distinguishing the colors of many different objects, I think it's easier to judge colors against a black background than against white.

    @supercat I disagree

    @Shimmy: How many different colors of text or thin-line-graphic objects would you be able to easily distinguish against a white background?

    @supercat For me it's much easier to distinguish colors on a white background. I'm talking about recognizing those colors off screen. Maybe in real life it's different.

    Any one line answer? Will change quickly my Putty background!!!

    Could you point to more recent research on this? Because these results may simply be attributable to the low quality displays of the 80s, or responsible for a significant part of them.

    I wish I had enough reputation to downvote this. White screens are straining on the eyes and can cause migraines. The cited studies were like short lab studied and not 8h work days.

    This is just plain wrong. SMH. Probably this "research" was done by headache medicine companies. When I have a white screen accidentally come up on my machine, I can actually feel the headache starting. It hurts my eyes and my instinct is to look away from it. The white screen actually causes pain. How could my body be so wrong? It can't. The "research" is obviously wrong, or I'm special :)

    This answer considers readability, but not fatigue.

    Personally, I loathe dark backgrounds, and view them as a way to look geeky. More importantly, I do a lot of teaching, and I find that it is _much_ harder to read a dark colour them on a projected screen. Now, I know that projectors are never up to the standard of a modern screen, and there’s always the issue of room lighting. However, the classroom monitors are not top-of-the-line either. I have the feeling that if it’s harder in poor conditions, then it’s probably harder in good conditions, and our brains have to work harder to get useful results.

    This research was done long before we knew about blue light. IANAO (I am not an ophthalmologist), but I imagine staring all day at an LED screen emitting high amounts of blue light is worse than looking at dark themes that have less blue in the spectrum.

    I've seen that second quote, that astigmatism is a reason why some people prefer light themes, all over the Internet, but I can't find a **source** for that quote. Was this written somewhere? I'd like to point my colleagues to this post, but I am loathe to parrot uncited/uncitable information.

    @Manngo I can ensure you that for some people (like me) they are **not** a *a way to look geeky*. I haven't been able to find the reason (actually that's why I am here, trying to find out), but for me a dark background with white characters is way easier to read.

    Can you add more detail on "While light mode performs better, those gain seem to be more short-term. Long-term exposure may be result in myopia." - this seems very important / dangerous

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Content dated before 7/24/2021 11:53 AM