f.lux is a free program that adjusts the color temperature of your screen according to the time of day. The program calculates adjustments based on your location and the type of lighting you use at night. This helps reduce eyestrain and improve sleep quality.
f.lux works by modifying the amount of blue light emitted by your screen. Blue light is the part of the light spectrum most likely to disrupt sleep. f.lux reduces the amount of blue light emitted by your screen at night, helping your body to produce more of the sleep hormone melatonin.
As the day progresses, f.lux will gradually adjust screen brightness and color temperature to match your environment, resulting in a more comfortable working environment and less eye strain.
If you find that the default night values are too warm (yellowish), you can adjust them from the settings dialog. The program can be temporarily disabled from the system tray icon whenever you need to display colors accurately (e.g. for photo or design work).
Note: This option is now available in Windows 11, but I find that f.lux is more flexible and offers more settings.
Here's a summary of the benefits of f.lux
Reduces eye fatigue
Improves quality of sleep
Reduces the risk of age-related macular degeneration (AMD)
Reduces the risk of cataracts
Improves cognitive performance
Helps you let go and get back to bed for a better night's sleep
OS: Windows, Mac OS
Language: English
Price: Free