Blue light from TVs, cell phones, and computer screens has been cited as one of the biggest culprits causing the sleepless epidemic in our modern, high-tech society. Many people buy blue light-blocking apps, glasses, and screen covers in an attempt to stop the allegedly harmful rays from disrupting their sleep cycle. It turns out that those sweet blue light-blocking glasses that you wear at night may not be entirely necessary.
Scientists at the University of Manchester just made a discovery that flies in the face of conventional wisdom about sleep: Blue light actually ISN’T as disruptive to sleep patterns as we previously thought.
Why isn’t blue light responsible for poor sleep habits?
The team found that blue light isn’t responsible for keeping us up all night, but that bright lights in general are the actual culprit. Researchers who conducted the study claim that using dim, cool lights in the evening and bright, warm lights during the day is most beneficial for our health.
The teams’ findings make sense when you consider the fact that twilight is both dimmer and bluer than daylight; both features that our bodies use to make sure we fall asleep and wake up at appropriate times.
What the study found
Current technologies that are designed to help us sleep by blocking blue light, such as glasses and software, work by changing the screen color on your device. The scientists who conducted this study believe that this sends your body mixed messages, since the color that your screen changes to resembles the same color as daylight. Obviously daylight is not conducive to sleep, hence why most of us use blackout curtains to prevent the rays from creeping through in the morning.
The research was conducted on mice and used lighting that was designed to allow the team to adjust color without changing brightness. Blue colors produced weaker effects on the mouse body clock when compared to equally bright yellow light.
These findings could have an important impact on the design of screens and lighting to help ensure that people can properly stick to healthy sleep and wake patterns.
Dr. Tim Brown, senior lecturer at the University of Manchester, said: “We show the common view that blue light has the strongest effect on the clock is misguided; in fact, the blue colours that are associated with twilight have a weaker effect than white or yellow light of equivalent brightness.
“There is lots of interest in altering the impact of light on the clock by adjusting the brightness signals detected by melanopsin but current approaches usually do this by changing the ratio of short and long wavelength light; this provides a small difference in brightness at the expense of perceptible changes in colour.”
He continued: “We argue that this is not the best approach, since the changes in colour may oppose any benefits obtained from reducing the brightness signals detected by melanopsin. Our findings suggest that using dim, cooler, lights in the evening and bright warmer lights in the day may be more beneficial. Research has already provided evidence that aligning our body clocks with our social and work schedules can be good for our health. Using colour appropriately could be a way to help us better achieve that.”
The study was originally published in the journal Current Biology.