By Dr. Mercola
You may remember the blue-blocking sunglasses that were popular in the U.S. in the 1980s. The glasses, with their amber-colored lenses, had a bit of a cult following and were perhaps best known for how clear they made regular objects appear.
They were promoted by Joel Sugarman who is actually a friend of mine and regular reader of this newsletter.
However, many are not aware that these glasses were originally designed for the NASA space program. Astronauts need powerful eye protection in outer space, where ultraviolet (UV) rays from the sun are incredibly strong.
A sunglass manufacturer developed a special design that blocked not only the UV rays but also blue rays.1 The glasses had the desirable "side effect" of making objects appear sharper, but the real benefits of blocking blue light are only beginning to be understood.
Far beyond the benefits to your visual clarity, blocking blue light serves an important biological purpose, helping to regulate your internal clock to control sleep patterns and other body functions. Quite simply, avoiding blue light at night is crucial to protecting your health.
Why Exposure to Artificial Blue Light Needs to Be Avoided
Exposure to artificial light is one of the largest often-overlooked health risks of living in the 21st century. Your early ancestors had no such worries, as their day started and ended with the rise and fall of the sun, which synchronized perfectly with their circadian rhythm.
Today, your body is still attuned to this internal clock. In the morning, bright, blue-light-rich sunlight signals to your body that it's time to wake up. At night, as the sun sets, darkness should signal to your body that it's time to sleep.
The problem is that most people living in developed countries no longer go to sleep when the sun sets.
Instead, we turn on LED lights, computers, televisions, tablets and smartphones, all of which expose us to varying amounts of blue light at a time of day when there's supposed to be next to none. Your body is understandably confused as a result.
It's now becoming clear that one of the least expensive and simplest ways to protect your body's internal rhythm, and thereby support healthy sleep and a lowered risk of many chronic diseases, is to wear blue-light-blocking glasses not just at night but anytime you are exposed to artificial lights.
I found an effective Uvex model (S1933X) on Amazon that costs less than $10. I recommend purchasing a pair for everyone in your household and putting them on at dusk, as the sun sets.
I call them reverse sunglasses and wear them indoors in most commercial buildings that have their lights on and then I remove them the moment I go outdoors.
While you could alternatively buy special light bulbs for evening use and install programs to lower blue-light on your electronic devices at night, one $10 pair of amber glasses does the same thing for far less money and hassle.
The Benefits of Wearing Blue Light-Blocking Glasses
The benefits of blue-blocking glasses are immense and varied. In my view the primary benefit is to prevent damage to the DHA essential fat in your retinal pigmented epithelium which is responsible for converting sunlight into vital DC electric current your body needs.
Additionally blue light will increase the distance of the proteins in the respiratory electron transport chain in your mitochondria making them far less efficient in producing mitochondria.
Those who wore blue-blocking orange-tinted glasses from 6 p.m. to 8 a.m. for seven days had significant improvements in symptoms of mania compared to those who wore clear glasses. What's more, the improvements began after just three nights of use.
The dramatic results make sense in light of the relatively recent discovery of intrinsically photo-responsive retinal ganglion cells, which are receptors in your eyes that detect only blue light.
These receptors communicate with areas of your brain linked to control of your biological clock (hypothalamus) as well as mood and emotions (the limbic system).4
In 2009, research published in Chronobiology International similarly found dramatic improvements in insomnia and mood in about half of bipolar patients who wore blue-blocking glasses.5
Antioxidants May Help Protect Your Eyes From Blue Light Exposure
Zeaxanthin is an antioxidant carotenoid found in your retina, but it cannot be made by your body, so you must get it from your diet. Lutein is found in your macular pigment, which helps protect your central vision and aids in blue light absorption.
Both zeaxanthin and lutein are also found in high concentrations in your macula lutea — the small central part of your retina responsible for detailed central vision. Together, they're believed to serve two primary roles:
1. To absorb excess photon energy
2. Quench free-radicals before they damage your lipid membranes
As noted in a white paper: "Together, lutein and the zeaxanthin isomers absorb a broader spectrum of high-energy blue light, which offers greater protection of retinal tissue."6 Lutein and zeaxanthin are primarily found in green leafy vegetables, with kale and (cooked) spinach topping the list of lutein-rich foods.
You'll also find these nutrients in orange- and yellow-colored fruits and vegetables. (The word lutein actually comes from the Latin word "luteus," which means "yellow.") Organic, pastured egg yolks are also a good source.
Growing Awareness of the Importance of Chronotherapeutics for Health
Chronotherapeutics refers to therapies that shift sleep and wake times or otherwise treat a person according to his or her internal clocks in order to improve health and prevent disease.
The importance of such treatments, including paying attention to light-dark cycles and their impact on human health, is becoming increasingly known. Take, for instance, a recent animal study published in Current Biology.7
When mice were exposed to continuous artificial light for five months, it led to many adverse effects on their health, including pro-inflammatory activation of the immune system, muscle loss and signs of osteoporosis.
Importantly, when the natural light-dark cycle was restored, the mice rapidly returned to normal within a period of two weeks. The researchers noted, "These findings strongly suggest that a disrupted circadian rhythm reversibly induces detrimental effects on multiple biological processes."8
American Medical Association (AMA) Gives Warning About Blue Light-Rich LED Streetlights
At the 2016 Annual Meeting of the American Medical Association (AMA), the AMA issued new guidance for communities on how to "reduce the harmful human and environmental effects of high-intensity [LED] street lighting."
AMA Board Member Dr. Maya A. Babu said in a news release, "Despite the energy efficiency benefits, some LED lights are harmful when used as street lighting."9
The guidance focused on high-intensity LED lighting, which emits a large amount of blue light and appears white to the naked eye. Risks noted by the AMA include risks to nighttime drivers, including:
• Worse nighttime glare than conventional lighting
• Discomfort and disability caused by the intense lighting may "decrease visual acuity and safety, resulting in concerns and creating a road hazard"
The AMA also pointed out that blue-rich LED streetlights operate at a wavelength that adversely suppresses melatonin at night — far more so even than other types of light. The AMA noted white LED lights "have a five times greater impact" on circadian sleep rhythms than conventional street lamps.
This, in turn, may lead to problems with sleep and related conditions. They cited "recent large surveys" that found brighter nighttime light in communities is linked with:
• Reduced sleep times
• Dissatisfaction with sleep quality
• Excessive sleepiness
• Impaired daytime functioning
Bright Light Is Beneficial When Exposure Occurs During the Day
Artificial blue light should be avoided at all times, not just at night. It's important to understand that exposure to full-spectrum natural light from the sun (which naturally contains some blue light) during the day is balanced with red light and actually beneficial and necessary for resetting your internal clock.
If you want to get good sleep, in particular, you have to have properly aligned circadian rhythms, and step No. 1 is to make sure you get a sufficient dose of bright light exposure during the daytime. Your pineal gland produces melatonin roughly in approximation to the contrast of bright sun exposure in the day and complete darkness at night. If you're in darkness all day long, your body can't appreciate the difference and will not optimize melatonin production.
Ideally, to help your circadian system reset itself, get at least 10 to 15 minutes of light first thing in the morning. This will send a strong message to your internal clock that day has arrived, making it less likely to be confused by weaker light signals later on.
Then, around solar noon, get another "dose" of at least 30 minutes' worth of sunlight. A full hour or more would be even better. If your schedule is such that you have to get up and arrive at work before sunrise, aim to get at least that half hour of bright sunlight sometime during the day.
A Fool-Proof Plan to Avoid Artificial Blue Light
Your health depends on a regular light-dark cycle that, ideally, starts and stops at the same time each day. In addition to getting exposure to sunlight in the morning and at mid-day, you can protect the needs of your body's internal clock by following this fool-proof plan.
Anytime that you are exposed to artificial lights (whether they're LED, incandescent or compact fluorescent lamps [CFLs]) and turn off electronic devices to reduce your exposure to light that may stifle your melatonin production you will want to wear blue blocking glasses.
If using a computer or smart phone, install blue-light-blocking software like f.lux, which automatically alters the color temperature of your screen as the day goes on, pulling out the blue wavelengths. Sadly the appreciation of the dangers of artificial blue light in the day is not well appreciated so this program only comes on at sunset.
Once you have your glasses on, it doesn't matter what light sources you have on in your house. You can even wear these glasses outdoors at night if you'll be travelling in an area with LED streetlights. When you're ready to climb into bed, make sure your bedroom is pitch black. The slightest bit of light in your bedroom can disrupt your body's clock and your pineal gland's melatonin production.
It's a good idea to cover your windows with drapes or blackout shades to achieve this — especially if you have LED streetlights outside your bedroom window. If this isn't possible, wear an eye mask, to block out any remaining light.