Study 'absolves' the blue light of mobile phones, 'does not disturb sleep'

Blue light from smartphone and computer screens may not be the cause of the difficulty in falling asleep, as many experts claim. This was stated by a study published by Current Biology, according to which the intensity of light, and not color, is interfering with the 'biological clock'. Researchers at the University of Manchester have exposed some guinea pigs to different types of light, yellow and blue, at different degrees of brightness. The highest brightness was 'stimulating', regardless of color, while the less intense blue light is more 'restful' than the yellow one.

"These results reflect what happens in nature - explains the main author to Bbc Tim Brown -, during the day the light that reaches us is relatively white or yellow and has a strong effect on the biological clock, while more is going on evening turns blue, so if you want to avoid effects, a less intense blue light should be the right choice ". According to the expert, therefore, the systems used by current smartphones, which in fact 'turn' from blue to yellowish, are not optimal for limiting the negative effects. "These systems have a small influence on brightness - he underlines -, in our opinion it is not the best approach".