itself has not been scientifically tested to determine its efficacy, and the equivalent Apple program, Night Shift, was shown to have no effect on sleep outcomes (sleep latency, duration, efficiency and wake after sleep onset) in a 2021 study on 167 college undergraduates. f.lux has been widely and positively reviewed by technology journalists, bloggers, and users. See also Electronic media and sleep Red Moon (software) Redshift (software) Light-on-dark color scheme References External links The Benefits of Avoiding Blue Light Before Bedtime: how filtering out blue light from screens improves sleep quality. 2009 software Utilities for Windows Utilities for macOS Utilities for Linux IOS software Usability Sleep Proprietary cross-platform software