• Tag Archives gtk
  • The Case for Dark System Themes: How to Save your Eyes and Use a Computer at the Same Time

    When I was young(er than I am now), I didn’t like black deco.  I thought it was evil.  I thought that a computer, used for word processing, should always have a white background just like a sheet of paper.  I thought that the command prompt with it’s white text on a black background was archaic.

    And I was in good company.  Even Apple seemed to agree with my sense of UI deco.

    Then I started to use a computer.  I started to really use a computer, like 10 to 12 hours a day, eight days a week.  I quickly discovered that staring at little shadows on a big square light bulb was not good for my eyes.

    This made me completely reconsider my sense of digital UI deco, and to collect a set of tools to help me reduce eye strain.  I present them here as that’s what this blog is for!

    System Theme

    Always find a plain black theme.  Not a black theme with fancy accents that makes your window trim look like it was painted and waxed in a Porsche Body Shop; a matte black with minimal fanciness is the best.  In KDE, I use the Oxygen-Dark theme.  I’ve also downloaded other theme components that provide green accents rather than blue.  I prefer black and green, especially when I’m running Linux Mint.

    Edit: Firefox has always been troublesome on a dark theme, because if the website doesn’t include full styling for text fields and form input elements, it will mess up their display.  This page shows you an easy and excellent way to fix that: http://ubuntuforums.org/showthread.php?t=1715031

    Note: I’ve never had luck with LibreOffice and a dark system theme.  When I need to do anything that needs to see colors, I have to change the system theme temporarily.  Does anyone know a solution?  EDIT 2014 02 06: It works!  See below:

    Office Apps

    LibreOffice / OpenOffice can work, even in Dark Themes!  If you do a lot of word processing in Writer, then this won’t help you save your eyes, but it will help you see the document as intended.

    Do this:

    • Open LibreOffice or OpenOffice
    • Tools > Options…
    • LibreOffice > Accessibility
      • UNcheck the option to automatically detect high contrast mode
    • LibreOffice > Appearance
      • Make the document background White, instead of Automatic (or a shade of gray to reduce eye strain)
      • Make the application background gray, to reduce the contrast between the white paper and the dark borders
      • Make the font color Black.
    • Click OK, quit Office, and open it again.  Now your presentations and spreadsheets will work as they should.


    RedShift or F.Lux

    These two tools (you only need one of them) tint your computer screen towards warmer colors based on the time of day.  The “white” light emitted from your monitor can be described in terms of color temperature, a measurement in Kelvin.  Basically, a “low temperature” white, say 5000K, will have a “warm” redder color, while a “high temperature” white, around 7000K, will have a “cool” bluer color.

    The important point here is that the color of your monitor should match the color of the ambient lighting to reduce eyestrain.  For a typical office with warm light bulbs and sufficient windows, the ambient light color will go from warm in the morning to cool at midday, and back to warm.  RedShift makes the assumption (and is generally correct) that this is the case, while F.Lux has a more complicated configuration to match any ambiance.

    If you’re using a laptop, then I recommend RedShift as a good general case, as staring at a warm colored monitor while in a room lit by cool lighting is not half as straining as the other way around.  On the other hand, if you are at a fixed computer with predictable ambient lighting conditions, then install F.lux and configure it to perfection.

    On Linux, either of these programs can be downloaded from the repository.  Install redshift and gtk-redshift (the control panel), and configure it to auto start when you log in.  Make sure your system clock is set to the right time zone and location, redshift will do the rest.

    Note: You will want to disable these tools when you are doing color-sensitive work, previewing images, and watching movies for the best results.  It’s usually simple: just click on the icon near the clock in your system tray.


    I used to use Compiz, which had a most wonderful feature: I could invert the color of any window I was looking at.  This is only really useful if you are reading a PDF: black on white.  Invert the window, and you have white on black!  Much better for the eyes.  Now my system no longer has Compiz, and the new compositors don’t seem to have that live-saving feature.  Hopefully it will come back…

    Regular Breaks

    Regular breaks (every 20 or 25 minutes or so) where you stare at some very distant object, such as the scene out the window, do wonders.  I must confess I’m not the best at following this particular piece of advice.


    Well, there you have it!  My toolkit for reduced eye-strain, and longer productivity.  Enjoy!

    You may ask: Why is this website all black-on-white?  The truth is that I haven’t yet overridden the default CSS to switch it to white-on-black.