Blue Light & Sleeping

By: Charlotte Miller

“The use of light-emitting electronic devices before bedtime may contribute to or exacerbate sleep problems” (Shechter et al., 2018). 

How many times have you been told to not use your phone before you go to sleep? Or not to stay up too late on your phone because it disrupts a good night’s sleep? Throughout quarantine, I have made a conscious effort to try to spend the last thirty minutes of night reading, rather than being on my phone. Although I am not always successful in this endeavor, I have noticed that it has helped me fall asleep faster and wake up feeling more refreshed when I do stick to my no phone bedtime routine. 

The positive results of this habit motivated me to learn more about why electronics can be harmful at night. Recently, I listened to a podcast that discussed the benefits of red light versus blue light for nighttime. Blue light is emitted from electronics, like a phone, TV, and computer. As I have mentioned in my article about melatonin, the body’s circadian rhythm is regulated by the suprachiasmatic nuclei (SCN) in the hypothalamus, the part of the brain responsible for regulating body temperature and the sleep and wake cycles (Zisapel, 2018). The SCN is controlled by light and dark, or daytime and nighttime. “Light, in addition to tuning the SCN, acts to inhibit melatonin synthesis” (Zisapel, 2018). Thus, using electronics at night can have a negative effect on circadian rhythms by disrupting the SCN and the release of melatonin. This in turn, can inhibit the physiological functions that the body begins  to shut down when it starts to get dark outside. So yes, it is bad for you!

But what if I use blue light glasses?! This is a question that has come up quite recently since the stay-at-home order was mandated. Stay-at-home led to the new normal, work from home. Investigating the usefulness of blue light glasses can guide your decision to buy them, or not.  

Blue Light Glasses: The New Trend

Let me break this down for you. Blue light gives off blue wavelengths which are beneficial for the body during the day (Harvard Health, 2012). There is even evidence that says it can aid in attention and concentration (Harvard Health, 2012), although for me, my phone usually just distracts me! Did you buy blue light glasses during the pandemic? I know I did. Taking virtual classes and working from home has definitely taken a toll on me. Staring at a screen for hours on end strained my eyes – a real condition dubbed computer vision syndrome – so I did what most people would. I went on Amazon and ordered blue light glasses. Blue light glasses serve to filter out the blue light emitted from electronics. They are advised to be used at night, or in the dark, when looking at electronics. Sounds amazing, but how well do these really work? I have tried to research the efficacy of blue light glasses and there is minimal research about the topic in general. They have certainly become a more recent trend as a result of the pandemic so the lack of research studies is not entirely shocking. My advice is to practice healthy habits with blue light at night and shut your devices down before getting into bed!

Night Time

Are you a night owl or an early bird? I am an early bird, which means I go to bed on the early side every night. Basically, I NEED my sleep. And at LEAST seven hours of it, or the next day I tend to be considerably cranky. What the available research does show is that at night, all forms of light can disrupt the body’s circadian rhythm. With the alteration of this internal biological clock, it can be difficult to fall asleep. The potential for a poor night’s sleep is an immediate red flag for me. Turning off my phone, other electronics, and any LED lights (which emit blue light) at least thirty minutes to an hour before I go to sleep is imperative to reach my desired sleep quality. Consistently exposing the body to unnatural light at night can result in a delayed and reduced melatonin release (Cajochen et al., 2011). If you care about the quality of your sleep, listen to the experts on this one. I know it is hard to put the phone down, or not watch the next episode, but actively trying to shut the electronics down at night can help both the mind and body. 

Reference List:

Cajochen, F. (2011). Evening exposure to a light-emitting diodes (LED)-backlit computer screen affects circadian physiology and cognitive performance. Journal of Applied Physiology (1985), 110(5), 1432–1438. 

Harvard Health, H Publishing. (2012, May). Blue light has a dark side. Retrieved December 16, 2020, from

Shechter, A., Kim, E. W., St-Onge, M. P., & Westwood, A. J. (2018). Blocking nocturnal blue light for insomnia: A randomized controlled trial. Journal of psychiatric research, 96, 196–202. 

Zisapel, N. (2018). New perspectives on the role of melatonin in human sleep, circadian rhythms and their regulation. British Journal of Pharmacology175(16), 3190–3199. 

Leave a Reply

%d bloggers like this: