Depression, mental illness, and general lack of achievement plagues modern society.
There are many causes for this… But one of them is lack of quality sleep. And it doesn’t get talked about enough.
Americans used to get enough sleep, and now we don’t. Between 1942 and 2013, the share of people getting less than six hours of sleep each night increased from 11% to 40%.
The damage that this has done to our mental and physical health is hard to overestimate.
We are weaker now than ever before, physically and mentally.
The decimation of our sleep schedules has coincided with our use of screens: TVs, computers, and — in the past decade — smartphones. This isn’t a coincidence.
How screen usage affects sleep
I first learned about how screen usage affects sleep quality (and quantity) when I came across my smartphone’s “blue light filter” setting.
At first I didn’t know what the big deal was. So I started to look for answers.
I’m going to give you the fruits of my research below. Both the dumbed-down, simplified version and the in-depth version.
The science: Short and simplified
Screens emit something called “blue light.”
This blue light isn’t bad on its own, but one of the things it does is it suppresses the secretion of the hormone melatonin, which regulates our sleep–wake cycles.
When we use screens before bed we are exposed to the blue light, which basically tells our brains that it’s daytime and that we shouldn’t get tired right now.
There are glasses out there designed to block the blue light from reaching our eyes. I tried a pair, and found the benefits were overwhelming:
- I got tired earlier
- My sleep quality improved
- My eyes didn’t feel as strained from screen exposure
If you want, you can pick up the glasses that I’ve been using for about six months now here: Read more
The science: In-depth
Now, I’ll go into more depth about the science behind it. This is something that really fascinates me (and doing the research meant I finally got to use my Physics degree in real life!), and I’m sure you will too.
About blue light
Most of the light you see is “white light.”
White light is a combination of all colors. Have you ever looked at light through a prism? Well, the rainbow you see is the white light being broken down into all its constituent colors. When you observe a rainbow in the sky after a rainstorm, the water particles in the air are acting as a prism to the white light coming from the sun.
If you’ve never met Roy G. Biv, you’re in for a treat. Actually, it’s not a person, it’s an acronym. And it describes the order of the separated colors that make up white light:
- R (Red)
- O (Orange)
- Y (Yellow)
- G (Green)
- B (Blue)
- I (Indigo)
- V (Violet)
Why am I telling you this? Well, for one, if anyone ever asks you the order of the colors of the rainbow, now you have this handy acronym to remember it by. But it will also come in handy shortly.
The electromagnetic spectrum
Okay, so now we understand what “white light” is. But actually, white light is just the visible part of the much larger electromagnetic spectrum.
Aside from white/visible light, the electromagnetic spectrum is also composed of gamma-rays, x-rays, ultraviolet rays, infrared rays, microwaves, infrared rays, and radiowaves.
Each of these (including the white light) is a type of ray of characterized by a certain wavelength. For the purposes of this article, I don’t need to dive into what exactly a wavelength is. For a more in-depth explanation, check this article out.
What you do need to know is that wavelengths are measured in nanometers (nm).
The wavelength of visible light ranges from approximately 740 nm (reds) to 340 nm (violets). As the ROYGBIV acronym would suggest, blue light exists at the lower end of the spectrum, somewhere between 435–500 nm.
Alright, now you know everything you need to know about the agents at play.
At this point, you might have the same two questions I had and couldn’t wrap my mind around for the longest time:
- If blue light is a natural component of light, then why is it suddenly so harmful?
- What is the exact relationship between blue light and melatonin? I hope I didn’t read all that science for nothing.
To answer these questions, we also need to know what melatonin is and how it works.
About melatonin (and why blue light is bad)
Melatonin is a hormone. It’s mainly secreted by the pineal gland, which is a tiny endocrine gland located at the center of your brain.
Melatonin is best known for the role it plays in helping people get to sleep, but there are a variety of other benefits derived from it. Melatonin is actually a powerful antioxidant that is responsible for:
- Lowering the risk of eye diseases such as age-related macular degeneration (Source)
- Treating stomach ulcers (Source)
- Alleviating heartburn (Source)
- Reducing the symptoms of tinnitus (Source)
- Increasing human growth hormone (HGH) levels in men (Source)
- Battling seasonal depression (Source)
- Reducing risk of prostate cancer (among others) (Source)
So melatonin doesn’t just help control your daily sleep–wake cycles. It may very well be the fountain of youth and health.
The secretion of melatonin is largely controlled by your body’s internal clock (also known as your circadian rhythm). Your circadian rhythm is influenced by the light you’re exposed to.
The amount of melatonin produced directly correlates to how sleepy you feel.
In other words: the more light there is, the more difficult it is to fall asleep. The darker the room is, the easier it is for you to pass out. Common sense, right? But it gets more interesting soon.
Typically, melatonin levels start to rise in the mid-to-late evening, after the sun has set. They stay elevated for most of the night while you’re in the dark. Then, they drop in the early morning as the sun rises, causing you to awaken.
This is why melatonin supplements are so popular for helping people get to sleep.
Now that you understand the importance of melatonin and the role it plays in sleep and health, let’s talk about blue light, why it’s bad for you, and how blue light blocking glasses can help you attain deep sleep and optimize your health.
Why blue light is bad for you (kind of)
So darkness causes the secretion of more melatonin, which makes you feel sleepy. But it’s actually a bit more nuanced than that.
See, not all light is created equal.
It turns out that the pineal gland is more sensitive to the wavelength spectrum of blue light than the other spectrums that comprise visible light.
While all light inhibits the production of melatonin, blue light does so much more powerfully.
Sleep researchers at Harvard University compared the effects of exposure to blue light and exposure to green light. They found that blue light suppresses the production of melatonin for about twice as long as green light does.
Blue light has always had this effect on melatonin production, but with the prevalence of digital screens, the modern human is exposed to way more of it than his ancestors ever were.
Between watching television, using the computer, or just looking at our smartphones, the only time most people do not expose their retinas to light is when they sleep. As a result, this means that we’re exposed to more blue light as well.
To recap everything so we fully grasp the significance of all this:
- Our modern environment is rife with artificial lights (digital screens, street lights, car headlights, home lighting, etc)
- Artificial light reduces hours of total darkness (we’ve never had so much brightness in the world)
- This light diminishes total melatonin secretion time and amplitude in both the short and long term
- Melatonin has a host of other benefits outside of sleep modulation (antioxidant, immunomodulatory, anti-cancer)
- Sleep is disrupted by the blue wavelengths that are present in all light. Sleep length (time) and quality (depth & REM) are diminished
- This has second and third order negative effects on our health (psychological, cardiovascular, and metabolic)
OK. Now let’s talk about the solution to the modern menace of blue light exposure.
The solution: blue light blocking glasses
As the name suggests, blue light blocking glasses block out blue light. More precisely, blue light blocking glasses filter the spectrum of visible light ranging from 350–600 nm.
And they work: researchers at the University of Toronto found that those who wore blue light blocking glasses produced more melatonin than those who didn’t during night shifts.
Now, personally, I researched a bunch of different blue light blocking glasses to see if there was any functional difference between them. Turns out, there is. The glasses I ended up buying are made by Carbonshade. More about them and their glasses below:
Carbonshade review: Six months in
The reason I chose Carbonshade’s glasses was not because of price (they’re not the cheapest option on the market). Nor was it because of the range of styling options (their glasses come in just two different models).
The reason I chose them was something I learned during my research into blue light that makes all the difference in the world.
See, most glasses I found had orange or amber lenses. But it turns out, red is the best color — and Carbonshade makes their glasses with red lenses.
Why does it matter? Because it’s not just blue light that interferes with our circadian rhythm: it’s also green light. Specifically, all light in the spectrum of 400–570 nm disrupts melatonin production:
“The shorter wavelengths of 470, 497, and 525 nm showed the greatest melatonin suppression, 65% to 81%. The shorter wavelengths also showed the greatest DLMO delay on night 2, ranging from 27 to 36 min. The results were consistent with the involvement of a scotopic mechanism in the regulation of circadian phase.”
(NB: 525 nm is the wavelength of green light, 497 nm is blue/green, and 470 nm is blue.)
But orange and amber lenses only filter out the blue light. Red ones block the whole range: both green and blue.
Unlike orange and yellow-lensed glasses which block less than half of the unwanted light, Carbonshade’s red lenses block over 99.8% of the light in this range. Their glasses have undergone laboratory testing to confirm their complete blocking power in this range.
The graph shows the light wavelength on the x-axis and the percentage that passes through on the y-axis. As the graph shows, Carbonshade glasses almost completely block out the visible light spectrum below 600 nm.
The exact percentages shown below the graph tell you exactly how much different wavelengths of light passes through. As you can see, in the relevant spectrums, it’s fractions of a percentage point. The “fail” or “pass” designations at the top of the page tells you if the glasses were successful in blocking that particular wavelength designation.
Quick aside: Near UV and Far UV rays return a “fail” result for transmission, but this is because they actually reflect those ranges (0–380 nm). This is indicated by the negative transmission percentage on the transmission report. This is important, because UV rays are also a problem, but for different reasons.
How blue light blocking glasses helped me, personally
I’ve been using the Carbonshades for about six months now. These are the changes I noticed.
I get tired faster
The first time I tried them on was sometime in July, at about 9 PM. Usually that time of the day, I still have a decent amount of energy left. But after about fifteen minutes of wearing my new glasses, I felt sleepy.
This makes perfect sense.
I usually spend my evenings working on my computer in a lit room. This means that my blue light exposure is massively disrupting my melatonin secretion.
Once I started blocking out the blue light, it was like a flood of melatonin got released, my circadian rhythm started to adjust, and I got sleepy.
Nowadays I use the glasses frequently, and have no trouble falling asleep in the evening. My “wind-down time” is a lot shorter.
My sleep quality is improved
I used to be a guy who gets up once or twice during the night to use the bathroom.
While urination is obviously a natural bodily function, the sleep disruption that accompanies it is not ideal. When I started using the glasses, my night time trips to the bathroom dramatically decreased.
I suspect this is due to another benefit of melatonin.
Low melatonin levels are linked to an increased likelihood of nocturia (night-time urination):
“Enhancing endogenous melatonin levels may be a preventive and therapeutic option for nocturia,” Japanese researchers concluded in this study. Another study also verifies the role that melatonin plays in controlling urination. The study concluded with this:
“Although the exact mechanisms of action of melatonin on bladder function is yet to be fully understood, there is a strong body of evidence suggesting that its imbalance has a detrimental effect on bladder dysfunction.”
In other words, lack of melatonin makes you have to pee more often — especially when you’re sleeping.
Blue light blocking glasses reduce the need to pee at night because they increase the amount of melatonin produced before you go to bed, greatly improving your sleep quality.
My eyes feel better
It’s time for another science lesson.
The shorter the wavelength, the higher energy the associated wave has. The waves that damage us — gamma rays, x-rays, and ultraviolet rays — have shorter wavelengths than even the color blue (< 380 nm).
The waves that we use to send communication — radio waves, television waves, and microwaves — have longer wavelengths.
Since blue light has the shortest wavelength out of all visible light, it carries the highest energy. And that energy does damage to our eyes.
When looking at computer screens and other digital devices, we’re staring into blue light more than our eyes are used to. Not only that, but oftentimes we’re also doing it well after sundown, furthering the unnatural strain on our eyes.
I deal with eye strain to the point where I’ve been using reading glasses when I work at the computer. If I don’t, my vision deteriorates shortly after sitting in front of the screen and I’m prone to headaches.
But when I use the Carbonshade glasses, I don’t need to wear my reading glasses.
My eyes not only feel rested, but I know that my eyes aren’t being strained because I don’t get headaches or suffer the blurry vision that comes from my eye strain.
Conclusion (and a call to action)
The blue light blocking glasses from Carbonshade have improved both my vision and general quality of life.
I initially got them because I was curious about the effect they would have on my sleep. They delivered in that realm, and they also relieved my eye strain and helped me get to bed earlier and faster.
I honestly can’t recommend these glasses enough. Especially if you spend a significant amount of time looking at computer or smartphone screens.
If my review of the Carbonshade glasses or my science lesson on the effect of light exposure on melatonin helped you make the decision to buy a pair, I’d love if you purchased through my link below. It’s an affiliate link, which means I get a small commission (at no extra cost to you). Not only do you support my writing, but you get a kick ass pair of glasses that will dramatically improve your quality of sleep and life.Get the shades here