In the past couple of years, companies have been adding a blue light filter to reduce the blue light coming from smartphones and PCs. This is done to ensure users have a better sleep at night and are not exposed to blue light in the hours before going to bed. This step was taken after many studies found that blue lights from screens are harmful for users and can mess up the sleeping pattern.
Unfortunately, a new study published by the University of Manchester challenges the previous claims. The study involved exposing mice to lighting that could have its colour adjusted without changing its brightness. When the mice were exposed to blue and yellow lights at the same brightness, researchers found that blue light had a less impact on the internal sleep clock than the yellow light. Dr Tim Brown explained the findings by pointing out an obvious issue with yellow or shades of yellow. While the yellow light provides warmer colours to the eyes at night, it also makes the body associate the light with The Sun. This changes at night when humans are exposed to more of a cold, blue colour due to the reflections from the moon.
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 … Our findings suggest that using dim, cooler, lights in the evening and bright warmer lights in the day may be more beneficial
– Dr Tim Brown
In conclusion, the researchers said that while the yellow light is easier on eyes, it makes the body thing it’s actually day and resets the internal sleep clock. Unfortunately, they concluded that there’s no obvious solution to this and the best way to get a good night sleep is to stay away from electronics before going to bed.