Researchers at Brigham Young University conducted a study to see how much blue light reduction features like Apple’s Night Shift improve the quality of sleep. Their conclusion? Night Shift doesn’t help at all.
In the study published in Sleep Health, BYU researchers assessed the sleep quality of 167 young adults, asking everyone to wear an accelerometer on their wrist before sleeping. Participants were randomly assigned three conditions for using iPhone before bed: one group did not use their iPhone at all, one group used their iPhone without Night Shift enabled, and another group did not use their iPhone at all. used their iPhone with Night Shift activated.
“There were no significant differences in sleep outcomes between the three experimental groups,” the researchers concluded.
For people who slept more than 6.8 hours per night, there was an improvement in sleep quality for those who did not use their smartphone at all. But Night Shift didn’t have a significant impact, and there was no difference between those who used smartphones and those who didn’t when the amount of sleep was less than 6.8 hours per night.
“This suggests that when you are very tired you fall asleep no matter what you did right before bed … the sleep pressure is so high, there really is no effect of what happens before. go to bed, ”said Chad Jensen, one of the researchers.
The researchers further postulated that mental stimulation, not the type of light displayed, plays a role in the quality of sleep for those who regularly get enough sleep.
The takeaway for users of these devices seems to be that the old adage holds up: avoiding using a smartphone before bed can improve your sleep. But the study undermines the common belief that features like Night Shift (which has its parallels in products made by companies other than Apple) can mitigate the negative effects of smartphone use on sleep.
“While there is a lot of evidence to suggest that blue light increases alertness and makes it harder to fall asleep,” Jensen explained, “it’s important to think about what part of that stimulation is light emission versus other cognitive and psychological stimuli. “