You’ve likely seen or heard somebody talking about blue light blocking glasses, but what are they? Do they work? Why do people use them? Today, I’m pulling back the curtain on all things blue light: its impact on our bodies and whether or not blue light blocking glasses make a difference for your sleep, productivity, and health.
What Is A Circadian Rhythm And How Does Blue Light Affect It?
Our circadian rhythm is a special rhythm that keeps our bodies in sync with day and night. It’s our internal 24-hour clock that is programmed to follow natural light and the setting and rising of the sun. When our eyes are impacted by external stimuli like artificial light– our biological clocks get confused and all out of whack.
When our internal clock is confused it affects everything we do from eating, sleeping, mating all the way to our pooping! Because of modern society and the way life works here in the US, our bodies no longer follow the sunrise, sunset schedule. Before Thomas Edison invented the light bulb in 1879, humans had to rely on the sun to structure their days.
Nowadays–we’re up working late on our computers, reading from our Kindles, and binge watching Netflix in our beds. All of this over working and over watching can be detrimental to our health and natural systems. That’s why it’s important to learn how to combat artificial light while still participating in modern day society.
Why the Sleep We’re Getting Isn’t Enough
Failing to get enough sleep (or enough quality sleep) can dictate everything from early mortality to diabetes and a whole lot in between.When our bodies are exposed to artificial light in the evenings, our melatonin fails to secrete. A recent Health Letter from the Harvard Medical School refers to several studies that link light exposure from working the night shift to breast, prostate, and other forms of cancer, as well as obesity, diabetes, and heart disease (2).
Losing just a small amount of sleep at night can repress your immune system; a study by the University of California found that “even a modest disturbance of sleep produces a reduction of natural immune responses and T cell cytokine production” (3).
How Does Blue Light Affect My Cortisol?
Scientists have also found a link between what they call a “flatter diurnal cortisol slope” and poor mental and physical health. This means that people whose cortisol levels spike naturally upon waking and are allowed to fall naturally at night are healthier than people whose cortisol levels spike at other times of the day or fail to spike at all (4).
But what causes cortisol to spike unnaturally during the day or remain elevated throughout the day? Stress. This includes stress that results from not getting enough sleep and the stress that is caused by artificial light pushing the body into adrenaline-producing mode.
Inadequate sleep may also interfere with your mental health. Researchers are looking at how a lack of sleep impacts conditions such as postpartum depression, while others already believe that a lack of sleep worsens conditions such as PTSD (5). Overexposure to blue light can result in excessive cortisol level spikes ultimately resulting in poor mental and physical health.
Sleep Deprivation Affects Everyone
Sleep deprivation doesn’t just impact our personal health; the Institute of Medicine of the National Academy of Sciences published a 2006 review that found 57% of fatal accidents and 20% of all serious car accidents can be connected to the driver being sleepy (5). We also know that a lack of sleep can cause response times roughly the same as if you were drunk.
Plus, there are major historical tragedies like the Exxon Valdez oil spill, the nuclear accident at Three Mile Island, and the space shuttle Challenger incident that were caused in part by lack of sleep (5). You might not be manning the next shuttle mission, but losing out on sleep puts yours and others health at risk.
Can Blocking Blue Light Help Me Sleep Better?
We now know that our circadian rhythm is deeply linked to our quality of sleep, and we know that artificial light makes a mess of everything. Why, exactly? Besides forcing us to stay awake or distracting us enough to stay awake, most artificial light today, whether it’s from overhead lights or from our television, computer, and devices utilizes large amounts of blue light waves.
Sunlight is composed of lots of different light wavelengths, but it’s thought that the blue light in sunlight is what stimulates our body to be awake and alert. Blue light therapy, for example, has been very successful in treating seasonal affective disorder and other kinds of depression (6).
In fact, when we’re not exposed to blue light during the day, we don’t feel good and our productivity diminishes. A 2008 study found that workers exposed to light enriched with blue experienced increased alertness and performance, and a drop in irritability, blurred vision, evening fatigue, and difficulty focusing and concentrating (7).
Turning Off the Blue Light at Night
The problem with blue light is over-exposure at night when we’re not supposed to be exposed to it anymore. Since blue light suppresses our melatonin production, our bodies still think that we’re supposed to be awake and productive when actually we’re supposed to be getting some quality sleep.
The data suggests many of us are struggling with this blue light problem. The National Institutes of Health report that roughly 60 million Americans struggle annually with insomnia, either briefly or for long bouts (8). Plus, while most adults need 7-9 hours of sleep each night, the CDC reports that more than a third of Americans report getting less than 7 hours of sleep (9).
Blocking blue light when the sun begins to set would fix many sleeping problems including not being able to fall asleep, waking up multiple times in the night, and not entering deep sleep.
How Much is Our Technology Costing Us?
For some of us, not getting enough deep, restful, rejuvenating sleep is due to an underlying medical problem such as sleep apnea, but for many of us, it’s because we’re burning the candle at both ends. Electronic devices and even light-efficient, blue-wave-emitting LED lights are proliferating rapidly and unfortunately, all this technological efficiency comes at a cost.
For example, when a Harvard trial shifted the circadian rhythms of ten study participants gradually, researchers noticed an immediate increase in blood sugar levels so high that people were thrown into a prediabetic state. Study participants also saw a drop in their leptin levels; which the hormone that makes people feel full after a meal (10).
Unfortunately, even the “dim” light of a table lamp is enough to interfere with melatonin secretion.
Can Blue Light Cause Blindness?
Blue light may even speed up the process of blindness for some people. Macular degeneration is the leading cause of blindness in the United States; 2 million new cases are diagnosed every year.
A University of Toledo study found that the retinal (molecules in our eyes that sense light and are vital to the process of sight) become toxic when exposed to blue light. It becomes a sort of killer cell that’s able to kill every other cell it’s exposed to–including photoreceptor cells.
Dr. Ajith Karunarathne, one of the study’s authors, explains, “We are being exposed to blue light continuously, and the eye’s cornea and lens cannot block or reflect it. It’s no secret that blue light harms our vision by damaging the eye’s retina.” (11)
Though this is extremely worrisome there are ways to mitigate the impact of blue light on our circadian rhythm and eyesight.
Do Blue Light Glasses Work?
Glasses that block blue light are simple, effective ways to minimize blue light’s impact on your body.
Here are a few recent studies that show extremely promising results:
- At the University of Toronto, researchers found people who wore goggles that blocked blue light at night had similar melatonin levels as people who were only exposed to dim light, without the goggles (10).
- A study published in the Endocrine Press found that people who wore blue light blocking glasses experienced the same melatonin production as people who were only exposed to dim light, while people who did not wear blue light blocking glasses and were exposed to bright light had very little melatonin production (12).
- In 2009, study participants wearing amber-tinted glasses that block blue light enjoyed improved sleep quality and improved mood (13).
A decade ago, we had few options for blue light blocking glasses. Most were ugly and clumsy, or even goggle-style. Fortunately, that’s not the case anymore! Blue light blocking glasses are available now in amber or orange-tinted lenses, or in clear lenses that only block blue light.
Why We Love Blue Light Blocking Glasses
Here’s why we recommend using blue light blocking glasses during the day and before bed:
- Using technology at night is like focusing a flashlight on your retina–the dark gives the light a magnifying effect. Sometimes, using a device at night is unavoidable; in those cases, blue light blocking glasses allow you to work without compromising your eye health or a good night’s sleep.
- Blue light blocking glasses minimize blue light’s impact on your eyes by helping to keep them from drying out. When we use our devices for long periods of time, we start to blink less, leading the cornea to dry out, which causes discomfort at best and serious eye problems at worse.
- If you, like us, sit at a computer most of the day for work, blue light blocking glasses help to cut down on the constant strain–our eyes weren’t designed to stare at bright lights all day!
- Blue light blocking glasses help us sleep better at night. When we combine them with other smart techniques for getting a good night’s sleep, we wake up feeling energized and rejuvenated.
Blue Light Blocking Glasses have a lot of benefits as you can see. If you’re constantly working on computers, scrolling through your phone, or even reading with a lamp on– blue light blocking glasses can benefit you! Get a better night’s sleep and wake up refreshed. Do you use blue light blocking glasses? Have you experienced the benefits? Comment below and let me know!
- Chan, S. & Debono, M. 2010. Replication of cortisol circadian rhythm: new advances in hydrocortisone replacement therapy. Therapeutic advances in endocrinology and metabolism, 1(3), 129-138. Abstract: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3475279/
- Harvard Health Publishing. Using these lights at night may harm your health. Retrieved from: https://www.health.harvard.edu/healthbeat/using-these-lights-at-night-may-harm-your-health
- Irwin, M., McClintick, J., Costlow, C., Fortner M., White, J., & Gillin, J.C. (1996). Partial night sleep deprivation reduces natural killer and cellular immune responses in humans. FASEB journal, 10(5), 643-53. Abstract: https://www.ncbi.nlm.nih.gov/pubmed/8621064
- Adam, E., Quinn, M., Tavernier, R., McQuillan, M., Dahlke, K., & Gilbert, K. 2017. Diurnal Cortisol Slopes and Mental and Physical Health Outcomes: A Systemic Review and Meta-Analysis. Psychoneuroendocrinology, 83, 25-41. Abstract: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5568897/
- American Academy of Sleep Medicine. (2007). Reduced Sleep Quality Can Aggravate Pre-existing Psychological Conditions. Retrieved from: www.sciencedaily.com/releases/2007/06/070613071126.htm
- Epstein, L. J. (2010). Improving sleep: A guide to a good night’s rest. Harvard Health Publications.
- Tuunainen, A., Kripke, D.F., & Endo, T. (2004) Light therapy for non-seasonal depression. Cochrane database of systematic reviews, 2004, 2. Abstract: https://www.ncbi.nlm.nih.gov/pubmed/15106233
- Viola, A.U., James, L.M., Schlangen, L.J., & Dijk, D.J. Blue-enriched white light in the workplace improves self-reported alertness, performance and sleep quality. (2008). Scandinavian journal of work, environment, and health, 34(4), 297-306. Abstract: https://www.ncbi.nlm.nih.gov/pubmed/18815716
- Center for Disease Control. (2011). Morbidity and Mortality Weekly Report, Vol. 60, No. 8. Retrieved from: https://www.cdc.gov/mmwr/PDF/wk/mm6008.pdf
- Harvard Health Publishing. (2018). Blue light has a dark side. Retrieved from: https://www.health.harvard.edu/staying-healthy/blue-light-has-a-dark-side
- Billau, C. (2018). University of Toledo. UT chemists discover how blue light speeds blindness. Retrieved from: http://utnews.utoledo.edu/index.php/08_08_2018/ut-chemists-discover-how-blue-light-speeds-blindness
- Gunnars, K. (2017). How Blocking Blue Light at Night Can Transform Your Sleep. Healthline. Retrieved from: https://www.healthline.com/nutrition/block-blue-light-to-sleep-better#section2
- Burkhart, K. & Phelps, J.R. (2009). Amber lenses to block blue light and improve sleep: a randomized trial. Chronobiology international, 26(8), 1602-12. Abstract: https://www.ncbi.nlm.nih.gov/pubmed/20030543