This study precisely illustrates the impact of screens on our sleep patterns

Do screens truly disrupt our sleep patterns? A recent study has sought to address this persistent question.

Blue light emitted from screens has garnered considerable attention for its alleged detrimental effects on sleep. However, recent research led by the University of Basel and the Technical University of Munich challenges this widely held belief. The researchers note that light plays a crucial role in regulating our sleep-wake cycle. Specifically, light with short wavelengths between 440 and 490 nanometers is perceived as blue.

In a 2019 experiment involving mice, it was found that yellowish light had a more pronounced effect on the internal clock than blue light. To delve deeper into this phenomenon, 16 human volunteers were exposed to both bluish and yellowish light stimuli for an hour in the late evening, along with a white light stimulus.

"This method of light stimulation allows us to separate the light properties that may play a role in how light affects humans," explained Manuel Spitschan, Professor of Chronobiology and Health at the Technical University of Munich. The results, however, were unexpected. 

"We found no evidence that variations in light color along the blue-yellow dimension play a significant role in the human internal clock or sleep," emphasized Christine Blume, a researcher at the University of Basel. Blume added, "Our results rather corroborate the conclusions of numerous other studies, suggesting that light-sensitive ganglion cells are the most crucial for the human internal clock."

Previous research has also yielded similar conclusions. An article published in the Journal of Sleep Research cited an experiment involving 58 adults who were asked to report their screen usage habits.

They were equipped with an electroencephalography (EEG) device to gather detailed information about their sleep quality. Surprisingly, the study found that screen usage before bedtime did not significantly affect sleep quality. In fact, in some cases, the total duration of sleep was even improved by engaging with certain media activities before bedtime, such as scrolling through social media or sending messages. 

"It was shown that the variation in light colour primarily does not influence the internal clock or sleep, but the brightness does. Light has this adjusting factor and is the most important zeitgeber for us to tell whether it is day or night. And if you see light at night or expose yourself to light at night, it's like a signal to your body: it's daytime, shift your internal clock so that it's right again." explains Professor Manuel Spitschan.