Leaked Windows 10 Insider build 14997 includes blue light filter
While the Windows Insider program is technically on holiday, that didn't stop insider build 14997 from leaking online today. The build contains a number of changes related to the post-installation setup, but the most interesting addition is a long-awaited blue light filter.
Blue light is the highest energy of all the light emitted by a display. The fact that it's high energy means it can damage one's eyes through extended exposure, but it also can affect sleep. Neuroscientists believe that blue light affects production of the sleep hormone melatonin more than other colors, and so it is recommended to avoid exposure to blue light in the evening or before bed.
"f.lux" is a popular blue light reduction application available for all major platforms, and Microsoft's built in tool will likely work the same way. Based on the screenshot, it likely uses a location-determined sunrise/sunset schedule to set the automatic reduction of blue light as well as a slider to increase or decrease the level of reduction.