Does blue light actually affect how we sleep?

Published : 23 Jan 2020 07:23 PM | Updated : 07 Sep 2020 06:42 PM

In recent years, there’s been an effort to combat blue light both in the office and at home.

Blue light is a color in the visible light spectrum that used to only come via the sun, but with digital devices all around us, from TVs, laptops, and smartphones, blue light is all around us. Even the lighting the office radiates blue light, which has both good and bad side effects, report agencies.

In some cases, blue light can increase alertness and help cognitive function while even elevating moods. At the same time, too much exposure to blue light can create eye strain which hurts your eyes and can even impede the ability to focus. While the world has adjusted by making efforts to limit screen time and the rise in blue light glasses, often seen in the office, it was once believed that blue light was the enemy for disrupting sleep patterns, but that might not be the case, according to a new study.

Scientists from the University of Manchester believe that blue light isn’t as disruption to sleep patterns as once thought. In fact, with the right combination of dimming lights in the evening and more vibrant, brighter lights during the day, it actually has health benefits. The study, published in the journal Current Biology, made its findings by testing mice by using specifically designed lighting that was designed to allow researchers to change the color of the light without manipulating its brightness. 

What researchers found was that blue colors had fewer effects on the rodent’s body clock compared to brighter colors like yellow.

“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,” said Dr. Tim Brown from the University of Manchester in a statement. “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 color.”

Researchers said that it makes sense to use cooler lights at night. At twilight, it’s dark dimmer and bluer than daylight, which allows the body clock is able to determine the times to be asleep and the times to be awake.

As it turns out, Brown said he advises against making adjustments like dimming your phone light.

“We argue that this is not the best approach, since the changes in color may oppose any benefits obtained from reducing the brightness signals detected by melanopsin,” he said. “Our findings suggest that using dim, cooler, lights in the evening and bright warmer lights in the day may be more beneficial.