f.lux™ free download better lighting for your computers.

Ever notice how people texting at night have that eerie blue glow? Or wake up ready to write down the Next Great Idea, and get blinded by your computer screen? During the day, computer screens look good—they're designed to look like the sun. But, at 9PM, 10PM, or 3AM, you probably shouldn't be looking at the sun.

f.lux makes your computer screen look like the room you're in, all the time. When the sun sets, it makes your computer look like your indoor lights.

In the morning, it makes things look like sunlight again.

Tell f.lux what kind of lighting you have, and where you live. Then forget about it. f.lux will do the rest, automatically.

Configuring f.lux

• How do I find or change settings?
  Settings are located in a menu to the left of your system clock. In Windows, this is at the bottom right corner of your screen. On a Mac, it's at the upper right. NOTE: f.lux does not appear in your dock, settings, or your alt-tab menu. Currently settings are only acessible through the taskbar.
• I installed this but it looks too pink/orange.
  On first use, it can take a while to adjust to the halogen settings. Try adjusting the color temperature sliders under Settings until you find one you like. Start with fluorescent or halogen and change it when your eyes adjust. When you disable f.lux, your screen will return to your normal calibration. We're used to looking at very blue computer screens, so it can seem unnatural at first. Most LCD displays are calibrated to display at 6500K, which has even more blue than noon sunlight (5500K). 
• I installed f.lux but I can't see any change.
  Is it past your local sunset time? Just wait, and f.lux will kick in at sunset.
  Is your location set correctly under Settings?
  Check that your night-time settings are not set to Daylight.