MANCHESTER, England — As smartphones have become an increasingly common part of our lives, many people’s eyes have become glued to their phone’s screen. Moreover, it’s very common for people to spend the last hour or so of their day on their smartphone. As the day winds down and we all look for a bit of relaxation, many can’t help but fall back on their favorite mobile apps or games. However, in recent years a prevailing belief has emerged that staring at a smartphone or laptop emitting blue light just before bed makes it harder to fall and stay asleep. Surprisingly, a new study is challenging this notion, and suggesting that blue light may not be as bad for our sleep as many believe.
According to researchers from the University of Manchester, using dim, cooler, blue lights in the evening and more harsh, bright lights during the day is actually right in line with what our bodies expect, and overall more beneficial to our health than detrimental.
The study’s authors used the Earth’s own sunlight patterns to illustrate their point: twilight is dimmer and bluer than daylight in the afternoon or morning. The human body has used these environmental cues to know when to sleep and wake for our entire existence. Thus, staring at blue light from a smartphone at nighttime, to our bodies’ internal clocks, is akin to observing the tame, dim light from the sky as the sun sets on another day.
As more and more people have adopted the belief that blue light harms sleep patterns, many tech manufacturers and companies have started rolling out device options intended to cut down on blue light exposure, such as the ability to change screen color on smartphones. However, the research team say such modifications may actually cause our phone screens to appear more similar to daylight, ultimately doing more harm than good by sending our bodies confusing mixed signals about bedtime.
To come to their conclusions, the researchers carried out a series of tests on mice, using custom designed lighting that allowed them to change the light’s color without adjusting its overall brightness. They discovered that blue light had less of an effect on the mice’s body clocks than yellow light that was equally as bright.
The study’s authors believe their work should be considered by designers attempting to create visual displays that promote healthy sleeping habits.
“We show the common view that blue light has the strongest effect on the clock is misguided; in fact, the blue colors that are associated with twilight have a weaker effect than white or yellow light of equivalent brightness,” comments Dr. Tim Brown in a release.
“Our findings suggest that using dim, cooler, lights in the evening and bright warmer lights in the day may be more beneficial,” he adds. “Research has already provided evidence that aligning our body clocks with our social and work schedules can be good for our health. Using color appropriately could be a way to help us better achieve that.”
The study is published in the scientific journal Current Biology.