At a restaurant recently, a waiter asked me if my orange glasses were actually blue blocking glasses and said he had some too!
In short, they are glasses designed to block most blue light that a person encounters after it is dark outside. Think of them as reverse sunglasses. You wear them inside instead of outside and to block artificial light, but not the sun.
If you look at the research, it turns out that wearing silly glasses can serve a serious purpose!
Artificial light is still a relatively new invention to modern man, and exposure to this type of lighting may be drastically affecting our biology. For most of history, people rose and slept with the sun. Their circadian rhythm was effortlessly controlled by the light of the sun and moon.
Now, we experience light at all times of day and night. Electronics and artificial lighting emit blue light, which only occurs in nature during the brightest part of the day. So when we encounter light that would only occur in nature during the bright afternoon hours at 11:00 PM, our bodies get confused!
While light of any kind can suppress the secretion of melatonin, blue light does so more powerfully. Harvard researchers and their colleagues conducted an experiment comparing the effects of 6.5 hours of exposure to blue light to exposure to green light of comparable brightness. The blue light suppressed melatonin for about twice as long as the green light. It shifted circadian rhythms by twice as much (3 hours vs. 1.5 hours).
Research suggests that blue light after sunset can disrupt circadian rhythm and suppress melatonin production.
Think about it, until the invention of electric light bulbs, people relied on the sun for the majority of their light. After dark, they only used natural sources of light such as candles, campfires, and lanterns (all orange lights). With the dawn of modern electricity, we suddenly had the ability to stay up with lights on for many hours after sunset.
With computers, TVs, tablets, and phones, this use has extended even more, and these new technologies are especially high in blue light. We're only starting to understand the affects, but we know that artificial light at night impacts cortisol patterns, melatonin, and circadian rhythm.
This is the reason that recent research found that just one week of camping away from artificial light could fix many sleep problems!
Electricity and artificial lighting have drastically changed the world. Of course, they have many benefits, but they also give us the ability to mess with our circadian rhythm and our sleep cycles.
The most disruptive event in the history of biotime occurred on December 31, 1879 with the invention of the electric light bulb.
Researchers have known for years that shift workers and those who are regularly up late at night are at a higher risk for various cancers. More recent research shows that even recreational exposure to blue light for a few hours at night can also have a negative effect.
Shift workers and those up after 11:00 PM seem to be especially at risk for the negative effects of blue light. Yet, research is showing that any of us who are up after dark looking at sources of blue light (TV, computer, etc.) are at risk.
It is important to note that blue light in itself is actually a very good thing. Exposure to blue light (preferably outdoors) is important during the day to maintain proper circadian rhythm. It is only blue light at night that causes the problems. At night, blue light signals the body that it is still daytime (sunlight has a lot of blue light).
In fact, avoiding blue light during the day has been linked to depression and sleep troubles! It is important to get blue light, but only during the day when it benefits the body. I have a 10,000 lux light box (with blue light spectrum) that I use in the morning and on rainy days to help my cortisol rhythm for this reason.
Turns out, there is a simple way to reduce most of the blue light we see at night: blue light blocking glasses.
People exposed to regular dim light without wearing goggles.
Melatonin levels were about the same in the two groups. This strengthens the hypothesis that blue light is a potent suppressor of melatonin. It also suggests that shift workers and night owls could perhaps protect themselves if they wore eyewear that blocks blue light.
I notice a big difference in my sleep and my cortisol patters when I regularly wear blue light blocking glasses at night. From testing, I've found that my salivary cortisol pattern is drastically improved when I avoid blue light after dark.
A study of 20 adults who wore either blue-light blocking or ultraviolet-light blocking glasses for 3 hours before sleep found that both sleep quality and mood improved among those in the group who wore blue-light blocking glasses, compared to the ultraviolet-light blocking group.
Shift workers are at especially high risk for circadian rhythm disruptions, because of their non-traditional schedules. At study from Quebec's Universite Laval, studied nightshift workers who used blue-light blocking glasses at or near the end of their overnight shifts for 4 weeks. At the end of the study period, their overall sleep amounts increased, as did their sleep efficiency.
There is some evidence that blue light will increase the distance of the proteins in the respiratory electron transport chain in the mitochondria. This makes them much less efficient in producing mitochondria.
Of all the health related changes I've made, this is one of the easiest and most effective! I just put on my blue light blocking glasses when the sun goes down and take them off when I go to bed.
Metal Blue Light Blocking Glasses: These glasses are lab-tested to block 97% of blue light. I find that they actually make it easier to see in low light and are great for computer use as well. Here's another great metal option.
Kids Glasses: These glasses fit our kids so they each have a pair that we keep in a basket in our living room for family movie nights and regular use after dark.
Budget Friendly Option: I also have a pair of these really cute orange glasses that I wear around the house at night.
Reduce or avoid TV, computer, phone, etc. after dark.
Use an app like f.lux on computers and tablets. This automatically reduces blue light on these devices after dark.
Dim overhead lights or just use lamps with orange bulbs after dark. Our favorite way to do this is by using salt lamps to light our house at night. Bonus: They also help clean the air.
Get bright sunlight during the day. This helps keep circadian rhythm in check and get some Vitamin D at the same time!
5. More studies on blue light and melatonin available here.
Ever tried blue light blocking glasses? Would you wear orange sunglasses at night? Think it's weird? Share below!