Humans, for all natural history that we know of, have never been exposed to blue light after dark.
Because of this, our bodies are tuned to the color blue, only present in the daytime sky.
This attunement to blue tells our body that it’s daytime.
Daytime means we humans will produce cortisol to be awake and alert and stop producing melatonin, a hormone of darkness and sleep.
When we see blue after dark, our bodies destroy melatonin, lose many of the benefits of sleep, and set us up for long term health issues such as diabetes, heart disease, obesity, and cancer according to the National Institute of Health.
In order to minimize exposure to blue light at night, the very best thing you can do is to wear blue light blocking glasses.
If Blue Light is Necessary, Why Block it?
Blue light is present in the sun always.
Our bodies have receptors that decode blue light.
These receptors are called melanopsin.
Melanopsin reads the blue light in the environment and uses this information to produce hormones that keep us healthy.
The amount of blue in the environment also tells the body what time of day it is. There is a varying amount of blue from sunrise to noon to sunset. The body reads these levels to know what time of day it is.
Knowing what time of day it is, helps our body set circadian rhythm. Circadian rhythm is so important to human health that the nobel prize in medicine was given in 2017 for the study of circadian rhythm.
Every cell in our body contains a clock and these clocks are required to be set to the right time for optimal health.
Our clocks are set by the color and brightness of light.
When we live indoors and turn on lights after dark, we confuse our body and the melanopsin receptors into thinking it’s daytime. We mess up our circadian rhythm and cause chaos in the body.
Blue light at the wrong time of day is devastating.
Blue light after sunset tells the body it's daytime, releases stress hormone and keeps you awake, destroying the healing hormone melatonin and ruining your sleep.
In addition, strong blue light during the day from devices and overheads lights that are devoid of UV and infrared light can damage the eyes by causing too many free radicals in the eye without the mitigating effect of infrared light.
Blue light after dark has been shown to reduce melatonin and shift circadian rhythm.
Why Wear Blue Light Blocking Glasses at Night
When the sun sets, melatonin is released from the gut and pineal in the brain into the blood. Melatonin stays high for about 12 hours and helps us clean up cancer and even boosts our immune system!
But artificial light, which has a high amount of blue light at a time when nature provides no blue light, messes with melatonin levels.
Blue and green light have both been associated with decreasing melatonin, blue more than green. Red light does not decrease melatonin.
When blue light is removed at night, people sleep longer and get better sleep and melatonin is preserved.
Blue light blocking glasses have been shown to filter out blue light and preserve melatonin.
Blue Light Blocking for Better Sleep
Wearing blue light blocking glasses after sunset have been shown to improve sleep and reduce insomnia. Personally, I find these glasses so effective that I gave a TEDx talk about the effect HERE and also developed my own blue light blocking glasses because good looking effective blue light glasses on the market were too expensive and I wanted everyone to have them.
Blue Light Blocking to Control Cortisol Release
Cortisol is released with blue light, because blue is always present only when the sun is up. When the sun rises, we want to be alert and awake. This is because we are diurnal animals (we sleep at night and awaken during the day) as opposed to rats that are nocturnal animals.
Our biology is coded to the light.
Cortisol is a stress hormone, but also keeps us alert and awake, which is fine during the day but not before bed.
Blue Light Blocking Glasses for Reducing the Risk of Disease
The National Institute of Health (NIH) has published multiple papers showing that exposure to artificial light at Night (ALAN) is associated with diabetes, heart disease, obesity, and cancer. In addition the World Health Organization has declared ALAN or artificial light at night as a Class 2B carcinogen, in the same category as microwave radiation, lead, and asbestos.
It's important to note that light at the wrong time of the day is likely carcinogenic and also leads to health issues. This is true for everyone, even if you do not "feel" like it affects you.
Protect your Eyes
If you work on a device all day or work under fluorescent or LED lights, you must protect your eyes. Daytime blue light blocking glasses filter some, but not all blue light to help protect the eyes.
Blue light during the day is necessary, but the intense blue light from devices is too much for your eyes and can create free radicals leading to macular degeneration.
Shift Work
Shift work is anti-life. I’m sorry about this, but humans are diurnal animals while rats are nocturnal animals. Humans are not nocturnal and this means no matter what kind of night owl you “think” you are, you are designed biologically to be asleep when it’s dark.
Yes, you can “try” to hack nightshift work, and HERE is our article on how we would hack nightshift if we had to work nightshift. Ultimately, you will want to find a new job that allows you to work during the day.
How to Choose Blue Light Blocking Glasses
Everyone and even all kids really need to be wearing blue light blocking glasses after dark.
We all are exposed to phones, devices, TVs and lights after dark, especially if we’re not at home where we can control the light.
The cheapest glasses you can buy are THESE and while they aren’t something you’d wear out of the house, you can definitely get the cheaply and try the out at home to see how they work for you.
We recommend you try them out for one month and see what happens. I haven’t yet met someone who didn’t notice a benefit.
For daytime blue light blocking glasses that look amazing, we made these glasses
Nighttime glasses that you can wear out of the house and look cool can be found here
Finally, if you want to block blue and green light at night, as both can mess with melatonin, then THESE glasses will do just that.
Other Ways to Avoid Blue Light at Night
- Use Red Lights in your home like these LEDs or Gembared (Discount code SLEEP) which can also be used for red light therapy.
- Add Twilight or Iris aps to your phone and use iris or F.lux on your laptops.
- Use Candles at night.
- Turn off the power in your bedroom at the circuit box. Many people do this to avoid EMFs as well..
- Get sunlight during the day. This has been shown to allow you to get better sleep at night.
As soon as the sun sets, put on your blue light blocking glasses.
When the sun rises the next day, take them off.
This will ensure you preserve your melatonin and build optimal health.