The feature can be turned on in Settings (in iOS) and in System Preferences (in macOS) and can be toggled on or off manually in the Notification Center (in macOS) or in the Control Center (in iOS). The Night Shift feature is compatible with all 64-bit iOS devices running on iOS 9.3 and above and Macs from 2012 and later running on macOS Sierra 10.12.4 and above. In mice, yellow colors disrupted the mouse body clock more than equally bright blue colors. Night Shift may make your screen darker, but Night Shift alone will not help you fall or stay asleep.Changing the color temperature of the display from blue towards yellow (without dimming the screen) 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 and to be insufficient for preventing the impact on melatonin suppression. “While there is a lot of evidence suggesting that blue light increases alertness and makes it more difficult to fall asleep, it is important to think about what portion of that stimulation is light emission versus other cognitive and psychological stimulations,” said Jensen. The psychological engagement experienced when texting, scrolling and posting are also important factors that affect sleep outcomes. The results suggest that it is not blue light alone that creates difficulty falling or staying asleep. “The sleep pressure is so high there is really no effect of what happens before bedtime.” “This suggests that when you are super tired you fall asleep no matter what you did just before bed,” explained Jensen. Within the six-hour group, which had the least amount of sleep, there were no differences in sleep outcomes based on whether the participants used Night Shift or not. The individuals who did not use a phone before bed experienced superior sleep quality relative to both those with normal phone use and those using Night Shift. The group that got seven hours of sleep, which is closer to the recommended eight to nine hours a night, saw a slight difference in sleep quality based on phone usage. The measured sleep outcomes included total sleep duration, sleep quality, wake after sleep onset and the time it took to fall asleep.Īfter not finding significant differences in sleep outcomes across the three categories, the researchers split the sample into two separate groups: one which averaged about seven hours of sleep and another that slept less than six hours each night. Individuals who were assigned to use their smartphone also had an app installed to monitor their phone use.

They were asked to spend at least eight hours in bed and wore an accelerometer on their wrist to record their sleep activity. The study included 167 emerging adults ages 18 to 24 who use cell phones daily. “Night Shift is not superior to using your phone without Night Shift or even using no phone at all.” “In the whole sample, there were no differences across the three groups,” Jensen said. To test the theory, BYU psychology professor Chad Jensen and researchers from the Cincinnati Children’s Hospital Medical Center compared the sleep outcomes of individuals in three categories: those who used their phone at night with the Night Shift function turned on, those who used their phone at night without Night Shift and those who did not use a smartphone before bed at all. However, a new study from BYU published in Sleep Health challenges the premise made by phone manufacturers and found that the Night Shift functionality does not actually improve sleep. Until recently, claims of better sleep due to Night Shift have been theoretical.

Night shift for mac app