Relieve Eye Strain With F.lux


Eye-Strain From Too Many Hours on the Computer

As you might imagine I spend way too many hours staring at my computer screen. Eye-strain is the result. For several weeks now after just a couple of hours of work I have been suffering from a mild but persistent headache right behind my right eye. I had to find a solution other than popping aspirin every day.

I began doing a little research on the internet and discovered there were several software options available. I tried a couple of them and F.lux is what I stayed with. Here’s my experience with this free little utility.

Installation and Use

Installation was straight-forward and there are no tool bars, Ad-ware, or browser home page changes to watch out for. How refreshing!

Once installed F.lux settles itself into your System Tray and its settings are only a click away. F.lux also sets itself up to run at Windows boot-time.

Versions of F.lux are available for Mac and Linux users too so no one is left out.

When you click on it, this is what you’ll see:


In order for F.lux to work correctly you will have to tell it where you live. You may enter your longitude and latitude (which you can find using your favorite search engine) or simply enter your ZIP code. In the above screenshot you can see that it’s well after sunset at my office and I am still plugging away with my computer. I have no life…

The 4000K at the top of that window displays the current screen color “temperature”. This has nothing to do with hot and cold, but how much blue there is in the color your screen generates. Higher numbers mean more blue relative to the other primary colors.

Color temperatures over 5,000K are called cool colors (blueish white), while lower color temperatures (2,700–3,000 K) are called warm colors (yellowish white through red). – Source Wikipedia

For more information on how the color blue affects humans and sleep patterns, there is an informative article called “Trouble Sleeping?” that will give you some ideas.

Click the Change Settings Button to personalize F.lux for your locale and temperature preferences.


By using the sliders in the left panel you will see immediate changes to the color temperature on your monitor(s). The right panel allows you to set your location. There are also a couple Radio Buttons to choose how fast the color change happens. I’ve tried both options and like the 60 minute choice as I never notice it. The transition is subtle.

When you click the Change Button, F.lux will open a a little window for you to enter your location.


If you click the Locate Button, F.lux will open a page in your default browser. Once there, you will be able to select your location using a typical Google map. This page also defaults to sharing your location with Stereopsis, the makers of F.lux. If you don’t want to share this information be sure to change this setting. I don’t really see the harm in it as this information is readily available the world over anyway. Have you ever Googled yourself? You may be amazed by the results.

I think the real trick with this program is to get those sliders set correctly. You will have to experiment to see what works best for you in your particular environment.

Results and Download

I have three monitors and the utility works across all three simultaneously. I checked its memory usage and it comes in at a small 8MB.

You can get a copy of F.lux to try it out for yourself at the F.lux Download Page.

If you are a Chrome user, and have a single monitor, and don’t want an extra utility running in the background, there is an add-on called Sunglasses that may do the trick for you.

I’ve been using F.lux for four days now and I no longer have that nagging headache behind my eye. Obviously, I am going to recommend this light-weight, free software to anyone who spends way too much time using their computer.

One final thought

Eye-strain is not the only negative impact from long-term computer usage. Sitting, as it turns out, is very bad for you. According to the seemingly ubiquitous articles on this subject even if you exercise daily it won’t arm you against long bouts of sitting.

With this thought in mind I combat all the guilt I feel by keeping a little timer on my desktop. Every hour it beeps to remind me to get off my chair, walk around and stretch the old limbs a bit.

The one I use is TimeLeft by NesterSoft. It is flexible and you can set up more than one timer for any number of reasons you might think of. There is both a Free and a Paid version. The free version that I use reminds me about once a month that since I have been using the utility for so long, I must be enjoying it and finding it useful and therefore… <the logical conclusion to the previous premise>

How do you combat eye-strain and inactivity?

About The Author

4 thoughts on “Relieve Eye Strain With F.lux”

    1. Hello Chet,

      I’ve been using TimeLeft for a couple years now, I think. I have it set to sound off every hour to remind to walk away from the computer and actually use my legs from time to time.

      You can also set up several instances running at the same time. This will let you set alarms for different reasons.

      As for details on how to use the utility that might be a good idea for a future article. TimeLeft is easy to use. It is also flexible which leads to a lot of different setup scenarios. NesterSoft has a features page right here: http://www.nestersoft.com/timeleft/features.shtml

      It will show you all its various uses. there is also a page that will show you a bunch of screenshots to give you a better idea of how it looks and operates: http://www.nestersoft.com/timeleft/screenshots.shtml

      I’m sure if you start using it you will have it figured out in no time (no pun intended),

  1. linda thompson

    I have been using this for years! It is NOT complicated..set it .forget it!Just remember to disable it
    if you are working on photos so you can see true color,,it has a button to do this.
    I love it because so many websites use glaring bright white as their back round..and it kills
    my eyes! ENJOY IT..It is great!

    1. Hi Linda,

      I’m new to F.lux but I am enjoying it as much as you. I didn’t realize how long I had my behind-the-eye headache- the realization just struck me one day.

      In any case, my headache is now gone and I agree with you that the bright white I was staring at for long hours was the problem. I tinkered with the brightness controls on my monitor but somehow that made things worse.

      F.lux seems to have fixed all that for me.

      Thank you for your comment,

Comments are closed.

Scroll to Top


Get great content like this delivered to your inbox!

It's free, convenient, and delivered right to your inbox! We do not spam and we will not share your address. Period!