f.lux is a simple program that alters the color temperature your computer’s monitor according to the time of day. During the day, your screen keeps the typical bright white look that you are used to. Once the sun sets, however, f.lux lowers the color temperature so that warmer reddish tones replace some of the bright whites and blues. The application’s developers suggest that this change may help you sleep by toning down the color temperatures you are exposed to before bed. Upon setup you simply let f.lux know your zip code so that it knows when the sun rises and sets in your area. You also let it know the type of lights you use in your room at night so that it can match the ambient color temperature of the room. I have it set so that the color change happens gradually over the course of an hour and I hardly ever notice it happening. If you prefer an abrupt change, you can set the software to make an instant switch.
I’ve been using f.lux for about six months now and I’m quite happy with the results. I can’t say for sure that my sleep has improved. I didn’t have much trouble sleeping before I began using the software. I do feel like it reduces the eye fatigue that accompanies long stretches of computer time at night. I’ve always been an advocate of changing your computer’s default window background color from white to a light shade of gray or blue in order to cut down on eye strain. f.lux takes those efforts to the next level.
Some f.lux users report that making a switch back from the warmer tones to the colder, brighter ones while you are working at night helps wake you up. The software has an option to disable the color change for one hour in case you need to do some color sensitive work. When I’ve tried this feature while working at night, the effect has been clear. Immediately the screen feels as bright as the sun, perhaps even a bit too bright to handle for the first thirty seconds or so. Quickly, however, your eyes do adjust. I don’t think I’d go so far as to say that this wakes me up, but it certainly does refocus my attention.
I wouldn’t recommend the software for anyone working with color sensitive material. If you are doing graphic design, for example, I doubt you’d want the colors on your machine fluctuating. But for those of us hammering away at word processing software night after night, this little program offers a small but generally pleasant improvement over the status quo.