Negative effects of blue light on your night’s rest

Getting enough sleep is very important. This fact is being underestimated a lot. Getting enough rest at night is critical for a good health. Getting not enough rest at night is being linked to various heart diseases, diabetes type 2, depression and it is also a strong risk-factor for obesity (Peri, 2014). The problem is not only that people nowadays do sleep a lot less compared to the past, also the quality of our night’s rest has declined during the years (Harvard Health Letter, 2012).
One of the biggest factors regarding sleep problems is the use of artificial lighting and mainly the use of electronics before bedtime. These devices radiate blue light, which tricks our brain into acting as if it is daytime (Harvard Health Letter, 2012).
Why is blue light essential during the daytime?
Our bodies have an internal clock, located in our brains, which orchestrates our sleeping rhythm. This so called circadian rhythm is not 100% accurate. Therefore, the body uses external signals to alter to the environment. The most critical factors for our internal clock to adjust to are daylight and darkness. During the evolution of humans, it was important to be able to find food during the day and to rest and sleep at night (Schmerler, 2015).
However, not all light is the same. The light of the blue wavelength, is mainly the one simulating the eye sending signals to the brain. It is important to know that the light of the sun is a mix of different wavelengths and thus also contains a lot of blue light. The blue light is important during the day, it helps us to stay alert, while improving our mood and performance (Schmerler, 2015).
Crucial during the day, a disaster at night
While blue light is a crucial factor to keep us going during the day, it is a complete disaster if we get exposed to this in the night. When the sky becomes dark at night, a part of the brain (pineal gland) releases the hormone melatonin. This signals the body and brain that they are tired and the time for sleep has come. Blue light effectively slows down the production of melatonin. The effect of using devices (sending out blue light) late at night, is that not only the number of hours of sleep get reduced, but also the quality of our sleep. Which as mentioned in the introduction can lead to various health problems (Schmerler, 2015). So, keep this in mind when working on that deadline late at night.
References
Harvard Health Letter (2012). Blue light has a dark side. [online] health.harvard.edu. Available at: https://www.health.harvard.edu/staying-healthy/blue-light-has-a-dark-side [Accessed 21 Oct. 2017]
Peri, C. (2014). 10 Things to Hate About Sleep Loss. [online] webmd.com. Available at: https://www.webmd.com/sleep-disorders/features/10-results-sleep-loss#1 [Accessed 21 Oct. 2017]
Schmerler, J. (2015). Q&A: Why is Blue Light before Bedtime Bad for Sleep? [online] schientificamerican.com. Available at: https://www.scientificamerican.com/article/q-a-why-is-blue-light-before-bedtime-bad-for-sleep/ [Accessed 21 Oct. 2017]