Wednesday, 10 July 2013

Change the colour temerature of your screen to reduce eyestrain

Following on from my blog about online marking, one reader raised the point about eye strain.  Of course eye strain can be a real problem if you are spending a lot of time working off a computer screen, and there are a number of practical steps you can take to reduce the problems this may create - For example, taking regular breaks and ensuring proper lighting.  Some sources suggest that the best kind of lighting for using a computer is about half the brightness of that which you find in most offices, and this would explain a lot about why so many people in bright offices are continually rubbing their eyes.

Another factor may be the brightness of your computer screen itself, and although I have absolutely no medical knowledge about this whatsoever (really, none at all) one discovery which has definitely made a huge difference to me is a computer program which changes the colour 'temperature' of the screen gradually according to the time of day.  In the mornings, the screen is brighter and more blueish, and as the day gets darker the screen becomes dimmer and uses warmer shades.

This 'before' and 'after' shot shows how the colour temperature of the screen is changed using F.lux

There are two programs which do this. I have tried them both, and to be honest couldn't really tell the difference between them - although one works better on Windows and iOS.  Both work beautifully on Linux.


The first one I tried was Redshift.  This wee program works well on Linux, but has only beta versions available for Windows - which means that it may be a little 'buggy'.  Until recently, Redshift only worked through the terminal as a command-line program, which means that you had to do a fiddly bit of programming to get the thing going.  It wasn't particularly difficult to do, but in the latest version of the program a GUI has been added which makes it even easier.

Ubuntu users can install Redshift directly from the repository, or if you prefer you can use the following commands:

sudo add-apt-repository ppa:jonls/redshift-ppa
sudo apt-get update && sudo apt-get install redshift


The second program is F.lux.  This one works fine on Windows, iOS or Linux.  You can install from the command line with the following:

sudo add-apt-repository ppa:kilian/f.lux 
sudo apt-get update sudo apt-get install fluxgui

Both F.lux and Redshift require that you input your longitudinal and latitudinal co-ordinates, so that the shifts in colour temperature correspond correctly to the time of day in your time zone.  Both now provide a simple link to a website where you can get this though, and it is simply a matter of copying and pasting from the website into the program.

Choose 'autostart' on each of them to ensure the program starts up automatically, and you never really need to think about them again - they will just work quietly away in the background, and the changes will occur so gradually that you will barely notice anything - except how much easier on the eyes it is.