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Blue Light: The Sleep Killer

Sleep is pivotal for every human being. Whether you are an adult or a teenager, a good night sleep can provide increased cognitive reasoning, wider attention span, and simply a good feeling to tackle the day. However, there are many ways in which we can get a lack of sleep or even a bad sleep. One of these ways is being exposed to blue light, a sleep killer. 

Blue light is on the visible light spectrum, which means it is a type of light that we can perceive with our eyes. We often come in contact with blue light through our usage of cell phones, computers, and TV. According to Shadab Rahman, who studies sleep at Brigham Women’s Hospital in Massachusetts, he stated that blue light can indeed negatively affect sleep. However, he furthers that fact by emphasizing how blue light can even disrupt the body’s circadian rhythm. The circadian rhythm is a body’s natural clock; it is the body’s mechanism to tell you when you should sleep. Therefore, blue light is a huge problem for people who are exposed to it especially with the technological advances we have now.

In a study conducted by Amit Shai Green, who is a Ph.D. student at the University of Israel, he and his peers recruited 19 people in their 20s and exposed a certain amount of people in the group each to various visible light through modified computer screens. These visible light were strong blue light, strong red light, weak blue light, and weak red light. In their data analysis, Green and his group analyzed the amount of time each group slept for, how many times they have woken up in the night, and when each person went into REM sleep (a phase which indicates when a person is in deep sleep). Additionally, for qualitative purposes, they also allowed each recruit to discuss how their sleep went the following morning.

Shockingly, recruits who were exposed to intense blue light had 16 minutes less sleep compared to those exposed to red light (which was the control in the experiment). Furthermore, they discovered that recruits with strong blue light had less melatonin, too. Melatonin is a hormone that signals the body to fall asleep when it is tired. Therefore, Green and his group concluded with convincing evidence that blue light can definitely affect one’s sleep and when a person would go to sleep. As a result. blue light offers low melatonin levels that affect one’s circadian rhythm. This can be detrimental for those who need a minimum amount of 8 hours of sleep, especially for children.

Ultimately, we can see how blue light can be known as a sleep killer. For those who love being on the bed with their phone before going to sleep, who love watching television, or playing on the computer, the blue light emitted can negatively affect your sleep. Rahman advises that electronics should be turned off two hours before going to sleep. Perhaps mom was right that sunlight may be the best light for us after all.


Editor: Maria ‘Stefi’ Ticsa


For more information, click here and read more about how to reduce the effects of blue light here.