Why are blue-light-blocking glasses, or “blue blockers,” so controversial? What are they supposed to do, and what does the science say about them? What’s the difference between filtering and blocking? And lastly, we’ll cover what you ought to pay attention to should you decide to shop for a pair.
Chapter 1: Filtering versus Blocking Blue Light
Chapter 2: Blue-Light Filtering Glasses For Eye-Strain
Chapter 3: Blue Light Blocking (Blue blockers) for Natural Melatonin Production
Chapter 4: Melatonin: the super hormone
Chapter 5: Evidence that blue-blocking glasses work
Chapter 6: FAQ about nighttime blue blockers
—FAQ: Who should wear nighttime blue blockers?
—FAQ: When should you wear nighttime blue-blocking glasses?
—FAQ: Do blue-blockers have to be orange?
—FAQ: Can’t I just use sunglasses?
—FAQ: How long does it take to see results?
—How often should you wear nighttime blue-blocking glasses?
—FAQ: What if you work the night-shift (doctor, nurse, etc.)?
—FAQ: What colour lenses should I get? Amber or red?
—FAQ: What type of frames should I get?
Bonus chapter: Fix your environment for maximum melatonin production
Filtering versus Blocking Blue Light
There is a lot of heated debate around “blue-light blocking glasses,” and I believe it’s because the debate often lumps in two totally separate problems and their own unique solutions.
So let’s first notice the difference between:
- blue-light filtering glasses which are clear (or sometimes slightly tinted yellow) and meant for the daytime.
- true blue-blocking glasses, which are typically yellow, amber, or even red, meant for nighttime.
Second, we need to talk about what problem each particular pair of glasses are trying to solve.
- The clear, daytime blue-filtering glasses only remove a small amount of blue-light, typically between 10–60% of blue light, and the goal is to reduce eyestrain from long hours on the computer. According to a 2011 review, up to 90% of people get some sort of eyestrain when using the computer for a long time.
- The amber, nighttime blue-blocking glasses aim to remove 100% of blue light with some removing most of all green light as well. The goal is to allow maximum natural melatonin production at night that is currently disrupted by using artificial light after sundown. Artificial lighting at night from common things like house lighting, street lighting, and screens like TVs and phones. This artificial light at night can stop melatonin production. Melatonin is a hormone only made by our bodies in the dark that improves all aspects of health, including fertility, cutting cancer risks, recovering from lifting weights, fighting colds, and more. (we’ll cover all of this in more detail soon.)
Blue-Light Filtering Glasses For Eye-Strain
So, clear glasses like Felix (blocks 13% of blue), Pixel (blocks 14% of blue), Warby Parker or many lenses offered at your local optometrist can have an extra blue-light filtering coating. The idea is that blue-light coming from your office computer, fluorescent and LED lighting can cause eyestrain and possibly damage your retina.
Do blue-light filtering glasses work?
In 2017, a systemic review found three studies looking at blue-light filtering lenses and was published in the Journal of the College of Optometrists.
The first thing they found is that there was no difference between regular lenses and blue-light filtering lenses on:
- contrast sensitivity
- colour vision
In one study on eye strain / eye fatigue, the clear blue-filtering lenses did not cause any benefit over the regular lenses.
The study found a slight benefit if using “strong” blue-light filtering glasses (these ones were slightly brown-tinted) for “pain around/inside the eye,” “eyes were heavy,” and “eyes were itchy.”
So, if you’re a programmer or spend all day in artificial lighting, it might be worth experimenting with “heavier” blue-light filtering, perhaps even like the popular Gunnar gaming glasses, which are tinted slightly yellow. It doesn’t seem like cutting out a modest 10–20% of blue and having clear lenses mostly unaffected will do enough for combating eyestrain.
As of the time of this 2017 review, there were no direct studies on blue-light filtering glasses and macular health. This is a bummer because there are a lot of worries between the connection of age-related macular degeneration and blue light.
The authors wrote:
There is a need for high-quality studies to address the effects of blue-blocking spectacle lenses on visual performance, and the potential alleviation of symptoms of eyestrain and/or visual fatigue.
So, in terms of eyestrain and blue light filtering glasses, we might be on our own to make inferences on our own, do our own experiments such as trying a heavier blue-light filtering tint, and see what work’s best.
The good news? So far, there seem to be no known side-effects. Researchers wrote:
None of the included studies reported on adverse effects associated with the use of blue‐blocking lenses.
My opinion on blue-light filtering glasses
I’ve bought specific computer glasses in the past but stopped wearing them. I wasn’t suffering from eyestrain but was looking to optimize health and productivity. But today I am wary about the potential of a small shift in magnification affecting my eyesight (I could see better than 20/20 vision the last time I was checked.) But if you’re struggling with eyestrain, experimenting with a “stronger” blue-light filtering like the Gunnars, which can be bought at 35% (slight tint) and 65% (yellow tint) of blue removed.
And if I needed prescription glasses, I would be personally wary of coating my all-around glasses with blue-light filtering. Blue light from a natural source like the sun is normal, healthy, and may have additional benefits we have yet to discover. By cutting out natural blue light too, well, we don’t know what complex systems we’re playing with. For example, so let’s say you’re walking to work or eating lunch outside on a nice day, you’d want those natural blue-light rays coming from overhead from the sun. Natural blue-light has energizing and anti-depressive effects, so the goal isn’t to get rid of natural blue light, but to avoid beaming copious amounts of artificial blue light directly into your eyes via LEDs for 12 hours straight.
Software instead of glasses
If you want to minimize your blue light inside as you work without buying blue-light filtering glasses, you can shift the colour of your screen using software:
- F.Lux—Free. I use this during the day on my computer, and I turn off occasionally when I need to double-check colours on something.
- Iris—$$ but gives a lot more control. I used Iris at night since it allows me to shift the screen completely red with 100% of green/blue removed.
If you have control over your workspace, you can also install incandescent lightbulbs, or orange coloured LED bulbs, which emits much less artificial blue-light compared to fluorescent or regular LED bulbs. We cover this a bit more at the end of the article. At my home office, I work near a window and have a red/near-infrared bulb for alternative reasons (red light therapy), so I don’t really need any more lighting otherwise.
My personal opinion is that if you want to minimize eyestrain, the two elements you can change are the environment and your recovery.
- At work, change your screen colour or wear heavy blue-light filtering (tinted) glasses.
- Try and take breaks outdoors where you can get some natural sunlight exposure (don’t wear glasses or sunglasses), take a brisk walk outdoors around and try and look as far in terms of distance as possible to give your eyes some variety. There’s a reason nearsightedness (myopia) is accelerating at a rapid pace in today’s world, and it’s likely due to a lack of sunshine (pupil constriction, UV stress, etc.) and focusing on far distances.
Blue Light Blocking (Blue blockers) for Natural Melatonin Production
Blue-light blocking glasses are attempting to block all of blue light, and some try to block all green light as well. They have lenses that are orange, amber, or sometimes even red.
To block artificial lighting at night, once the sun has gone down, to maximize melatonin production.
Throughout human civilization, once the sun would set, the human body would be in relatively complete darkness. There may be a fire, lamp, or candle, but those light sources are:
- orange and red
- relatively dim and not very bright
- are located below our head and don’t cast light from above (this matters, believe it or not, we’ll cover this later.)
So, once our body was in darkness, it would begin to turn from an “active” mode and into a “recovery” mode. It primarily does this by producing a hormone called melatonin.
Melatonin: the super hormone
Melatonin is most well-known as being a drug used for jet-lag or as a sleep aid. But it’s a powerful hormone our body produces naturally and it does much, much more than just help you sleep. The benefits of melatonin include that it:
- anti-obesity effects like telling fat to be burnt rather than stored, regulating cytokines, ( 2013 study )
- protects us from cancer, heart disease, and diabetes ( 2017 study , 2017 review)
- lowers blood pressure (2006 study, 2015 study)
- improves your brain (neuroprotection) (2016 study, 2016 study, 2016 study)
- protects us from viral transmission (2014 study, 2017 review)
- is a powerful antioxidant—even more powerful than vitamin C or beta-carotene ( 2015 study , study )
- might reduce our appetite—lowering cravings for late-night snacking ( study )
- helps with fertility and having a healthy pregnancy ( 2014 review )
- makes you look better by looking younger and more youthful ( study , study )
- can help you build muscle through better tissue repair and activating growth factor synthesis ( study )
Once the sun sets, and the body is in darkness, it will begin producing melatonin.
But the problem is that today’s artificial lighting stops and surpasses natural melatonin production.
In a 2001 study, researchers found that different colours of light in the room radically affected people’s natural melatonin production by as high as 81%. Blue, cyan, and green light negatively affected people’s melatonin the most. Yellow light affected melatonin a little bit, and red light did not seem to affect melatonin much at all.
Let’s say it’s winter in the North, and it becomes dark at 5 pm. Most people turn on bright lights throughout the house and watch a bright 4K television that covers the screen. Around 11 pm, they stumble down the hall and turn on their bright bathroom light and brush their teeth. In that example, all of those light sources are emitting lots of blue and green light, and our hero has theoretically lost over 6 hours of melatonin production to restore and become stronger, healthier, and more anti-fragile for the next day.
The simplest solution would be to stop using any electrical lighting the moment the sun has set. (My wife and I did this and only lived by candle-light as an experiment, see this article.)
This idea is so incompatible with today’s modern life it’s laughable. No television, movies, or video games?
So the goal with blue-blocking glasses is preventing blue (and green) light from getting to your eyes to allow for natural melatonin production allowing for maximal health and a pleasant wake-up experience in the morning.
I was skeptical for a while because we know that skin has the ability to sense light (and beyond, it can protect itself from UV and feel infrared heat, for example.) Why would just protecting our eyes help while leaving our skin exposed?
But there are numerous studies showing that blue-blocking glasses do actually work.
Evidence that blue-blocking glasses work
In a 2018 study, researchers took first-year college students with sleep problems and gave them blue blockers.
those wearing amber glasses first tended to sleep longer and have fewer awakenings at night than those wearing blue lenses
Not only did they get better sleep, but their mood also improved as well. And all those benefits disappeared once researchers switched out their amber, blue-blocking lenses for blue coloured lenses (making everything blue.)
In another 2018 study, researchers looked at people who were either doing endurance or weight-lifting training and blue light exposure at night. One group got amber lenses, and the other got clear lenses as the control. All of them had moderate to good sleep already. They put the glasses on 3 hours before bed.
In as little as nine days of using them, researchers found:
Results indicate that blocking short-wavelength light in the evening, as compared to habitual light exposure, significantly shortened subjective sleep onset latency, improved sleep quality, and increased alertness the following morning.
In a third 2018 study, researchers compared using blue blockers at night versus opening the blinds early in the morning. Researchers measured their melatonin levels and found:
We found that a decrease in evening blue light exposure led to an advance in melatonin and sleep onset on workdays. Increased morning light exposure advanced neither melatonin secretion nor sleep timing.
…our findings show that controlling light exposure at home can be effective in advancing melatonin secretion and sleep…”
And in a 2009 study, one group wore yellow-tinted glasses while another wore true blue-blocking glasses that were amber. Researchers found:
At the end of the study, the amber lens group experienced significant improvement in sleep quality relative to the control group… Mood also improved significantly relative to controls.
This 2009 study also illustrated an important fact—it might take a longer time for the blue-blockers to work for some people. It took nearly three weeks for the averages to beat the control.
There are many more studies related to reducing artificial, blue light at night for improved health that we won’t cover today. A few more for those interested:
- 2009: Nighttime use of special spectacles or light bulbs that block blue light may reduce the risk of cancer.
- 2016: Wearing blue-light-blocking glasses in the evening advances circadian rhythms in the patients with delayed sleep phase disorder: An open-label trial.
- 2017: Blocking nocturnal blue light for insomnia: A randomized controlled trial.
Are there any side effects?
So far, none seem to be known. That doesn’t mean there aren’t any. Perhaps the slight pressure of glasses harms our faces over thirty years, maybe the slight change in magnification from the lenses isn’t good for our eyesight, perhaps seeing brightness but with certain colours cut off isn’t good for our rods and cones. Who knows. But we do have a good grasp of the benefits they have on sleep and melatonin in today’s world of artificial light at night.
FAQ about nighttime blue blockers
Who should wear nighttime blue blockers?
Theoretically, everyone could stand to benefit from removing artificial light at night as our body is used to complete blackness. Certain people may be more sensitive, though, such as kids who can see light more brightly and those with blue eyes. In terms of total health, women might stand to benefit the most from improved fertility, and older folks who need to protect what little melatonin they have. If you have kids and they stay up for a long time beyond sundown, you can try asking them to wear blue-blockers with you, or you may want to keep reading as we’ll cover some environment changes you could experiment with.
When should you wear nighttime blue-blocking glasses?
The moment it is naturally dark outside, and you start to turn on indoor lighting would be a good time to begin wearing your blue-blockers. My kids go to bed about 30–60 minutes after sundown. After they’re put to sleep, that’s when my wife and I put on our blue-blockers. We take them off and wash our face by candle-light, and take them off when we’re finished reading and are going to sleep.
Do blue-blockers have to be orange?
The orange colour comes from blocking all shorter wavelengths like violet, blue, cyan, and green. All that is left to see in terms of light is yellow and red—otherwise known as orange. So they’ll have to be orange, amber, or red if you want them to block the correct wavelengths.
Can’t I just use sunglasses?
No. Sunglasses still allow violet, blue, cyan, and green through. Plus, they darken the amber and red wavelengths, too, making it too difficult to see at night. (On a side note, I’m not even so convinced sunglasses are good for us even in the daytime. I’m thinking about converting my Ray-Bans into blue blockers—but that’ll have to be for another day.)
How long does it take to see results?
Some studies saw great results in as little as nine days, others as long as three weeks. I’d suspect the variance has to do with things like how bad their sleep was, to begin with, how red the lenses were, how long they wore them before bed, etc. If you are planning on experimenting with them, I’d commit to trying them for at least 30 days to see how you like them.
How often should you wear nighttime blue-blocking glasses?
You should wear them every single day unless you radically change your lifestyle and no longer use artificial light at night, or you radically change your environment to be free of blue/green light.
What if you already wear glasses?
There are a few options to consider:
- There are fit-over frames that are ugly, should you just want to experiment.
- There are clip-on versions of blue-blockers.
- You can buy prescription blue-blockers from a few manufacturers like RaOptics and BluBlox.
- If you’re convinced already, you could invest in changing your environment to be free of all blue-green light (the most work and money but also works well with kids and when guests come over. We cover this near the end of the article.)
What if you work the night-shift (doctor, nurse, etc.)?
There was one study showing that night-shift workers should wear blue-blockers immediately after finishing work in the morning for their commute home so that they don’t get any exposure to blue daylight so that they could fall asleep more quickly at home.
What colour of lenses should I get? Amber or red?
Theoretically, red would work better at protecting melatonin production. This is why I ordered a pair of high-end red blue-blocking glasses to replace my usual Uvex, which are amber coloured.
The problem I ran into is that red glasses cut even more wavelengths out—good for melatonin production but making everything much, much darker. I already have the lights low in my house after dark. I use task lighting and lamps. With the amber glasses, I can still see enough to get around the house. But with the red glasses, I couldn’t even see the stairs. I had to turn on lights to get the brightness I needed to navigate the house.
My opinion? If you want to leave all the house lights on or you’re using blue-blockers to visit family, go to the mall, going to the airport, working late at night at the office, studying in the library or whatever else—get the red lenses.
If you are just using the blue-blockers at home with most of the lights shut off anyways, then you may do better with amber lenses.
What type of frames should I get?
Basically, you can get two types of frames:
- Wrap-around frames that give you full coverage of your eyes. These frames are generally pretty ugly.
- Good-looking “fashion” frames that leave a ton of light to come in from the sides and bottom of your eyes. These frames can be bought to match your style and can look awesome.
I have both types, and my recommendations are to:
- Get wrap-around frames that are ugly for at home. The full coverage makes a remarkable difference. It really is noticeable. When it’s full coverage, it feels less like you’re wearing glasses since you can’t see the boundaries, and you aren’t getting any trace amounts of bright, blue light from the bottom and sides—especially if you’re in a brightly lit room.
- Get good-looking “fashion” frames that are less functional for in public like hitting the airport, hanging out with friends, etc. While they’re not perfect, they’re much better than nothing, plus you won’t look like you just came from target practice or from doing some hobby woodworking. Before I had any fashion frames, I opted to not wear my Uvex glasses to a Catan board game night and missed them. In hindsight, I wish I had a nice pair of Ray-Ban style club masters with amber lenses.
You could get a pair of inexpensive wrap-around frames to experiment with such as the Uvex. Should you like them, then get a nice pair of fashion frames, then upgrade your at-home Uvex to a higher-end home pair.
Best Wrap-Around Blue Blocking Glasses For At Home
|Uvex Skyper SCT-Orange Lens, Made in USA||<$10||Learn More|
|TrueDark Twilight Classic, Origin unknown||$90||Learn More|
|SafetyBlue Sleep Savior Ultra, origin unknown||$60||Learn More|
Best “Fashion” Blue Blocking Glasses For In Public
|BLUBlox, Parker Sleep+, Made in Australia||$120||Learn More|
|BLUBlox, Crystal Sleep+, Made in Australia||$115||Learn More|
|RaOptics, Herschel, Made in USA||$150||Learn More|
|RaOptics, Maxwell, Made in USA||$150||Learn More|
Which styles are your favourites?
Bonus: Fix your environment for maximum melatonin production
If you’ve got kids, have guests over frequently, or don’t like wearing blue blockers that much, you can hack your environment to be melatonin friendly.
Outdoor lighting coming in through your windows
If you live in the country, you won’t have outdoor lighting to deal with. For the rest of us with street lights and neighbours, we’ll need blackout curtains for our bedrooms, and probably some sort of blinds, curtains, or drapes for the main room you hang out in at night. Close those as the sun goes down.
For dinner in the dining room, we’re switching out our regular bulbs for Edison-style incandescent bulbs. While they still have some blue/green light in them, they’re much dimmer, and the colour temperature is much more weighted towards yellow and red. And they’re not so weird that you couldn’t enjoy a nice dimly lit dinner with them. The dimmer the light is, the less it’ll impact your melatonin production (study).
For lamps and task lighting, you can buy special amber or red bulbs (depending on how hardcore you want to go, remember yellow still had a bit of melatonin suppression but isn’t as weird.) These are an option:
For overhead lighting, I’d avoid replacing overhead lighting from what you use during the daytime (I’d recommend incandescent bulbs for a fuller spectrum weighted towards red.) There are two reasons. The first reason is that our eyes have the ability to tell if light is coming from overhead, like the sun. If the light comes from overhead, it is more likely to suppress melatonin compared to being below our eyes (2003 study). If you’ve ever wondered why lamps look better than turning on the overhead lights, this might be one reason why. The second reason we leave the overhead lights alone is that it’s a good idea to have the option to turn on bright white lights in case of an emergency. If someone gets sick or faints, you don’t want to be fooling around with amber or red lights. So once it’s sundown, stop using the overhead lights and switch to lamps instead with the right bulbs.
For appliances like fridges, stove lights, inside your clothes dryer drum, you might be able to replace the bulbs with an amber or red light. I’m still surprised by what I can buy on the internet. If you don’t want to do this, you could keep a pair of blue blockers next to the fridge.
For the little LEDs everywhere (routers, humidifiers, HEPA air filtering fans, etc.), you can use electrical blackout tape.
For screens like your TV and laptop, you’ve got three options:
- Software. For things like your laptop and phone, there are apps that will make your screen amber or red (100% blue and green removal). Just a heads up, the Apple Nightshift is not enough. It might be enough to remove some minor eyestrain at night, but studies have already found that it still has enough blue/green light to suppress melatonin. The best software at this time is Iris.
- Hardware. For the TV, you can install a box called DriftTV that will change the colours. The problem with this solution is that it’s not very future-proof. You’ll need to buy a new box for 4K, 5K, and whatever is next (8k?). If you’re a gamer who wants to save his health, I’d also be wary of how something like this would affect the response rate. Still, it’s an option for those who want a more automatic option.
- Coloured acetate sheets. These sheets will act like a “blue blocker” but for your TV. You can order one larger than your screen and cut it precisely to your screen size and enjoy television without needing to wear blue blockers. It won’t affect refresh rate, there will be no glitches, and it’s removable. The only question is one of optical quality.
If you’re struggling with eyestrain on the computer, try strong blue-light filtering glasses that are tinted slightly yellow. Research shows it may help a tiny bit. Or you could try shifting your work screen a bit more yellow using F.Lux or Iris.
As for the nighttime blue blockers—there are tons of people struggling out there with sleep. Their kids too. Wearing blue-blockers at night time is an inexpensive and easy solution to transform your sleep into a much better one.
Ideally, it’d be healthier to go back to no electrical light and to use candles and whatnot, but it’s not realistic for most people. And so, blue blockers can be a cheap option of reclaiming some of your health back. For those on the cusp of trying medication, why not order a cheap wrap-around pair, try it out for 30 days and see how you do?
And as we saw in one study, even for those who are already quite healthy, like someone who lifts weights or does endurance training, who already have a good sleep were able to improve their sleep and recovery.
If you like this kind of stuff and you’re a guy who wants to lift weights, you might like our True Gains program.
Otherwise, what did you think? Leave a comment below and I’ll respond.