Do Blue Light Blocking Glasses Work?

Growing public awareness of the importance of sleep has caused manufacturers to introduce many new products, from bedding to light bulbs, glasses, and software apps, often with unsubstantiated claims. Dr. Ceppie Merry’s in-depth article, Do Blue Light Blocking Glasses Do Anything? A Review of The Research, cites 26 scientific papers and reviews 8 popular claims about improved sleep and other health effects. The folks at her firm asked me to share it with you, so here’s a link to it with my own comments added.

CIRCADIAN RHYTHM — According to Dr. Russel J. Reiter, the world expert on Melatonin, this important molecule is found in every living organism, having evolved through millions of years of evolution to counter the oxidation harm caused by cell metabolism. Melatonin is nature’s strongest antioxidant, is critical to cell health, and is produced by the pineal gland as part of the circadian rhythm regulated by light and the day-night cycle. This natural cycle triggers behavior, whether signaling time to sleep or time to hunt. But as we age, we produce much less of it, and that’s worsened by the fact that artificial lights interfere with our biological clock. Reiter says there’s no such thing as taking too much Melatonin. Contrary to popular belief, taking supplements does not lower production of more from the pineal gland, since that’s entirely driven by the day-night cycle (actually by darkness). Reiter takes 30mg/day and keeps 150mg on hand in case of an emergency (heart attack or stroke), with strict instructions to give him Melatonin before oxygen.

ARTIFICIAL LIGHT — Artificial electric light has had a profound effect on human behavior, allowing us to work more but causing us to sleep less – almost two hours less than before Thomas Edison’s light bulb. That’s not natural and goes against evolution. Light color is also important, and we’re already seeing negative consequences of the bluish light of LED bulbs and backlighting of electronic devices. The fact that street lights and car headlights are using this energy-saving LED technology is also troubling, especially for shift workers who have trouble sleeping after staring into oncoming lights as they drive home.

HOME LIGHTING — In previous articles and lectures, I’ve described simple corrective actions around the home, giving all nighttime artificial lighting an orange hue. When buying LED bulbs for efficiency, look for those with the warmest color temperature, and dim them if your activity allows. If your clock radio has a white or blue face, replace it with a clock with a red face, or just turn it away so you can’t see the display at night. LED nightlights have way too much blue and can make it difficult to go back to sleep if you briefly wake up to go pee, so I suggest sticking with older models, replacing the incandescent bulbs with orange bulbs, or adding some sort of orange filter.

SMART LIGHTING — Philips was an early developer of smart lighting, with its color-changing Hue series. Dr. Merry’s article mentions the potential of using light to control mood, and Philips certainly plays in that space. They’ve even used lighting colors to control the mood, attention, and focus of school children, as shown in this video:

SMART SOFTWARE — Software that first appeared as apps to control the color of LED backlighting in phones, tablets, and PCs has finally been replaced by operating system settings. All of my devices now lower brightness intensity as the sun goes down and start removing blue light, leaving the screen with an orange tint while giving me the ability to override default settings if needed.

GLASSES & FILTERS — Wearing Amber Glasses at night can minimize the amount of blue light seen at night, but only wear them at night. Get bright light exposure as early as possible in the morning to also help regulate the circadian rhythm. If that’s not possible due to northern exposure or weather, resulting in seasonal effective disorder (SAD), use bright full-spectrum lights in the morning.

HEALTH IMPACT of Sleep

Dr. Merry’s report also examines various claims of positive health benefits of wearing blue light limiting glasses but seems to discount many manufacturer claims. Without arguing those points, I want to say that some of the health impacts of managing artificial light are related to improved production of Melatonin and its antioxidant role in fighting disease. Other benefits come from what happens in the body during the different stages of sleep, such as hormone production and activating the limbic system for waste cleanup. Here are some ways sleep wellness improves overall health:

Obesity – Sleep duration plays a role in regulating body weight and metabolism, because when sleep deprived, your body creates less leptin and more ghrelin. While leptin suppresses your appetite, ghrelin makes you crave carbs and is known as the hunger hormone. About two thirds of American adults are now overweight or obese, and we spend nearly $200 billion/year treating obesity-related illness.

Diabetes – Sleep deficiency increases the diabetes risk by 250%. Already, some 26M adults & children have diabetes, 79M are pre-diabetic, and every 10 seconds a person dies from diabetes related causes.

Heart Disease – According to a 2011 European Heart Journal review of 15 medical studies involving almost half a million people, sleep deficiency increases the risk of heart disease by 48%. So with over 600,000 Americans dying each year from heart disease, some 300,000 are likely related to sleep deficiency.

Stroke – The one third of working adults who sleep less than 6 hours a night are 4 times more likely to suffer a stroke. Each year about 800,000 Americans have a stroke.

Breast Cancer – Researchers in Japan found that women who slept less than 6 hours a night were 62% more likely to develop breast cancer than those who slept 7 hours. Other studies found that women who do shift work, such as nurses, have a higher risk of developing breast cancer than those who work during the day. That’s likely because of how light and melatonin regulates circadian rhythms. Sleep also affects recovery, and one study showed a 1.5-fold increased risk of dying from breast cancer among women who slept less than 5 hours a night before diagnosis compared to those who slept 7 or more hours.

Immune System – A well functioning immune systems protects us from colds, flu, and other ailments, but when poor sleep interferes, it fails to do its job. People who slept less than six hours a night were over four times more likely to catch a cold than those who slept over 7 hours.

Depression – Poor sleep is a contributor. A 2007 study of over 10,000 people found that insomnia increased their chance of suffering from depression 5-fold.

Alzheimer’s – Several new research studies have linked poor sleep to the loss of brain tissue, Alzheimer’s disease, and other dementia and neurological disorders; but it’s not yet clear just how much impact it has.

Premature Death – People who sleep less than 6 hours a night are 20% more likely to die in 20 years.

Birthrate – Declining birthrates are troublesome, because as boomers enter retirement years and live longer, they leave fewer young workers to contribute to the tax base and support social programs the elderly depend on.

Sources – This list of ways sleep affects health is taken from a a white paper I started years ago on “The Economic Benefits of Population Sleep Wellness” but never completed. I removed the reference links but can say the stats are from hundreds of articles published in scientific journals and mainstream media.