Why blue light is bad for you and how to reduce it

Natural blue light is emitted by the sun and it’s essential in regulating our circadian rhythm aka the sleep-wake cycle and body clock. It stimulates cortisol and suppresses melatonin production in the morning thus making us more alert. It also improves reaction time and a sense of wellness. In the evening, when the sun goes down, our body starts producing melatonin, the so-called sleep hormone.

Natural blue light is accompanied by all the other colours from the light spectrum, making it a healthy light source and body clock regulator. In countries where winter days are very short and dark, people often suffer from Season Affective Disorder, which lowers mood and heightens feelings of depression and anxiety.

So if blue light is healthy, why should we reduce exposure?

Unlike natural blue light from the sun, artificial light coming from digital devices and light bulbs are potentially harmful to human health because it contains far more blue compared to other colours in the spectrum. This excessive blue light penetrates the eye and over a day, will cause digital eyestrain. If you keep exposing yourself to it after the sunset, it will also reduce melatonin production and increase the release of adrenaline, dopamine, serotonin, and cortisol, which is the best recipe for insomnia and mental health issues.

Chronic excessive exposure to artificial light can cause:

• Computer vision syndrome (eye fatigue, blurred vision, dry eyes, headaches)
• Retinal cells damage and vision problems such as age-related macular degeneration
• Sleep disruptions and insomnia
• Depression and anxiety due to increased production of hormones like adrenaline, dopamine, serotonin, and cortisol

How to reduce blue light exposure 

1. Reduce your screen time

This is the easiest strategy that won’t cost you a thing. If your work description entitles staring at a computer screen all day, don’t watch TV when you come home. Go for a walk, read or listen to audiobooks and podcasts. Beware that many household appliances also emit blue light through their displays. Don’t use digitally lit appliances three hours before bed and don’t use a digital clock in your bedroom. 

2. Use blue light software and filters on your laptop and phone 

Use blue light filtering software on your computer and turn the display on your smartphone red. Although the latter doesn’t have a strong scientific backing, it’s worth trying.

3. Wear blue light blocking glasses

Blue blocking glasses are our favourite bio-hack when it comes to controlling the circadian rhythm and protecting our eyes from strain. There are three types of blue light blocking glasses- blue blockers, blue reducers, and blue/green blockers. You wear blue reducers during the day to avoid eyestrain and headaches and the other two to three hours before sleep to prevent disruptions to your sleep-wake cycle.  

Bon Charge are our favourite blue light blocking glasses. They are backed by science and made in Australia from the best quality materials. Find out more about the differences between blue light blocking glasses in their blog here.

4. Get in the sun!

Get outside at sunrise to let the brain set your body clock. Then get outside again at lunch for your second dose of full-spectrum natural light. The blue light wavelengths in sunlight help your brain maintain an optimal circadian rhythm including hormone production. Essentially, you want cortisol in the morning and melatonin at night.

5. Reduce blue light in your house

Another cheap and effective strategy is reducing blue lights in your house, especially in the bedroom. The bedroom should be only used for sex and sleep. Laptops, phones, tablets, TVs and any digital devices don’t belong there. To reduce blue light in the whole house, you can replace LED bulbs with blue light filtering light bulbs.

 

Veronika Larisova 
Co-founder, Nutritionist, Exercise Physiologist

 

 

 References:

• Burkhart, K., & Phelps, J. R. (2009). Amber lenses to block blue light and improve sleep: a randomized trial. Chronobiology international, 26(8), 1602–1612. https://doi.org/10.3109/07420520903523719
• Dabrowiecki, A., Villalobos, A., & Krupinski, E. A. (2020). Impact of blue light filtering glasses on computer vision syndrome in radiology residents: a pilot study. Journal of medical imaging (Bellingham, Wash.), 7(2), 022402. https://doi.org/10.1117/1.JMI.7.2.022402
• Esaki, Y., Kitajima, T., Ito, Y., Koike, S., Nakao, Y., Tsuchiya, A., Hirose, M., & Iwata, N. (2016). Wearing blue light-blocking glasses in the evening advances circadian rhythms in the patients with delayed sleep phase disorder: An open-label trial. Chronobiology international, 33(8), 1037–1044. https://doi.org/10.1080/07420528.2016.1194289
• Leung, T. W., Li, R. W., & Kee, C. S. (2017). Blue-Light Filtering Spectacle Lenses: Optical and Clinical Performances. PloS one, 12(1), e0169114. https://doi.org/10.1371/journal.pone.0169114
• Sasseville, A., Paquet, N., Sévigny, J., & Hébert, M. (2006). Blue blocker glasses impede the capacity of bright light to suppress melatonin production. Journal of pineal research, 41(1), 73–78. https://doi.org/10.1111/j.1600-079X.2006.00332.x
• Vitaterna, M. H., Takahashi, J. S., & Turek, F. W. (2001). Overview of circadian rhythms. Alcohol research & health : the journal of the National Institute on Alcohol Abuse and Alcoholism, 25(2), 85–93.
• Wood, B., Rea, M. S., Plitnick, B., & Figueiro, M. G. (2013). Light level and duration of exposure determine the impact of self-luminous tablets on melatonin suppression. Applied ergonomics, 44(2), 237–240. https://doi.org/10.1016/j.apergo.2012.07.008
• Zerbini, G., Kantermann, T., & Merrow, M. (2020). Strategies to decrease social jetlag: Reducing evening blue light advances sleep and melatonin. The European journal of neuroscience, 51(12), 2355–2366. https://doi.org/10.1111/ejn.14293
• Computer vision syndrome (CVS) is an umbrella term for a pattern of symptoms associated with prolonged digital screen exposure, such as eyestrain, headaches, blurred vision, and dry eyes.