||This article's tone or style may not reflect the encyclopedic tone used on Wikipedia. (September 2012)|
|Developer(s)||Michael Herf, Lorna|
|Initial release||February 2009|
|Stable release||Windows: v3.9
Mac OS X: build 23
|Operating system||Microsoft Windows, Linux, Mac OS X, iOS|
|License||Proprietary, with free download. (with patent claim)|
f.lux is a computer program written by Michael Herf of Stereopsis. It adjusts the computer display's color temperature according to the location and time of day, based on a user specified set of longitude and latitude geographical coordinates.
The program was designed to reduce eye strain during nighttime use.
f.lux is also available on the iPhone, iPad and iPod Touch, though it requires the device to be jailbroken. The developers are also said to be working on a version for the Android operating system.
f.lux is based on the idea that adjusting the color temperature of the display to match the current time of day will not inhibit the secretion of melatonin during night time, thus allowing the user to sleep with ease. Bright and blueish lights, such as natural sunlight, inhibit the creation of melatonin in the brain to signal the beginning of the day. Most computer, tablet, and touch phone displays, however, also emit a blue light that triggers this inhibition, affecting the user's ability to sleep and potentially disrupting the user's sleep cycle. When night time arrives, f.lux automatically adjusts the color temperature (making whites appear reddish or salmon), thus reducing the display's brightness to match the room's lighting. The change is noticeable at first but turns imperceptible after a few seconds.
f.lux automatically calibrates the computer display's color temperature to the time of the day. The user also has the option of choosing a color preset or disabling f.lux for an hour and returning the screen to its normal calibration. The software offers five preset color settings on OS X: candle, tungsten, halogen, fluorescent, and daylight. For Microsoft Windows, the halogen, fluorescent and daylight settings, as well as Incandescent on beta, are available.
The software requires the device's location in order to determine its local sunrise and sunset. Currently it does not work for people living more than 65 degrees North.
- f.lux: F.A.Q
- Cajochen C, Frey S, Anders D, Späti J, Bues M, et al. (2011). "Evening exposure to a light-emitting diodes (LED)-backlit computer screen affects circadian physiology and cognitive performance.".
- f.lux: F.A.Q