I need you to tap into your inner 5-year old for a moment.

Think like a kid again and ask yourself, “Why’s the sky blue?”

Although it's a cute question every little kid asks, the answer isn’t trivial when it comes to your long term health.

The changing colors of the sky are actually important clues as to what frequencies of visible light are making it through the Earth's atmosphere at various times of day.

The daily light cycle is important because these different frequencies interact with the cells of your body to set crucial hormonal and physiological cycles into motion.

Or at least that's what should happen if synthetic light sources weren't around to bombard us with the entire visible light spectrum 24 hours a day!

After reading this article, you'll understand what frequencies of the visible light you should pursue or shy away from at critical times each day. This will not only help you to sidestep some serious chronic health risks in the future but also boost your daily spunk and productivity at the same time!


Sunlight, Rainbows and Your Biological Clock

Without dragging this post down into a hardcore physics lesson, I'll just tell you that the sky is blue during the daytime and reddish-orange during sunrise and sunset hours because of how sunlight interacts with the Earth’s atmosphere.

Sunlight contains the entire visible light spectrum, which is why it can be separated into ROYGBIV rainbows by droplets of moisture in the atmosphere.

When the sky changes to a reddish-orange hue around dusk and dawn, the atmosphere has basically filtered out most of the blue spectrum in the sunlight making it to your particular spot on planet Earth.

Understanding this is important because the circadian rhythms of your body evolved to thrive on these daily cycles of light frequency exposure.

However, with the explosion of electricity and light emitting devices since the late 1800’s, your biology is now overwhelmed by synthetic light that's now causing a plethora of unintended health consequences.

Chronic disorders such as sleep deprivation, serious hormonal imbalances and cognitive degeneration are exploding at accelerating rates. The world’s circadian rhythms are become increasingly confused by the prevalence of 24-hour, light-emitting technology across all of our lives.

Of course, none of us want to give up the many benefits of our increasingly empowering technologies, but we must find ways to merge them more gracefully in our lives to respect and recapture our biologic balance.

Modern Day Light Pollution

Pre-electricity, the only light exposure you could be exposed to after sunset was candle, torch and fire light.

It turns out that fire light is nothing like synthetic light sources because the light it emits is primarily infrared (a.k.a. heat) and red-oranges in nature. Basically, campfire light is similar to dawn and dusk light and doesn't appear to interfere with daily sleep-wake cycles of your body.

On the other hand, light emitted from light bulbs, computer screens and smartphones is more analogous to the “blue sky” light of daytime.

The point here is that exposure to most light bulbs, computers and smartphones at night confuses your biological clock into thinking that it’s day time when it's not! Ultimately, this interferes with important daily hormonal cycles that are crucial to your health, longevity and day-to-day feeling of restfulness.

How Light Impacts Your Long-Term Health

Look, there's nothing inherently dangerous about visible light however, improper synthetic light exposure interrupts the production cycles of two crucial hormones – Vitamin D and Melatonin.

The basic relationship between these two hormones is that Vitamin D and Melatonin levels rise and fall inversely to each other within the body.

Vitamin D begins to rise as the body is exposed to blue light in the morning. As this happens, Melatonin decreases. When the Sun begins to set and your blue light exposure falls, Vitamin D levels also decrease and which signals Melatonin production to ramp up in preparation for it's daily rest-and-digest phase.


Essentially, Melatonin plays an executive role in your sleep-wake cycle and is arguably one of the body’s most potent anti-inflammatory hormones. Chronically low Melatonin levels can not only cause lifelong sleep disorders, but also lay the degenerative groundwork for poor immune health, accelerated aging, dementia, pulmonary diseases, diabetes and many cancers.

Vitamin D

It’s also no secret that the general population has become Vitamin D deficient due to modern day life. We wear excessive amounts of clothing and are constantly indoors. Our wild ancestors evolved to thrive in a very different set of daily environmental conditions to say the least.

Exposure to blue spectrum light from daytime Sun is the main stimulus for Vitamin D production in your body. And you guessed it, perpetually low Vitamin D levels are now linked to several chronic health conditions including heart disease, bone loss, thyroid issues, accelerated aging, autoimmune diseases, chronic pain, depression, diabetes and several cancers.

How To Transform Your Tech into a Modern Day Tribal Campfire

Look, don’t get me wrong. I’m actually on your side when it comes to maintaing your high-tech life!

I’m definitely not advocating a complete ban on computers and iPhones here.

Instead, I want to empower you with clever strategies so you can have your delicious high-tech cake and eat it too!

But in order to do this, we must first find the balance between honoring our biology with what it needs to thrive and then fitting modern technology in that biological framework appropriately.

But guess what? It's really not that hard to get right!

Here’s 3 easy to implement strategies you can start using right away to make your modern day environment more like a hunter-gatherer campfire:

1. Use Software and/or Physical Blue Light Filters

The cat's out of the bag now when it comes to the negative effects of blue light spectrum emissions from computer and mobile devices at night.

There are now several software and physical products available to effectively combat synthetic light emissions without actually having to give up using your technological marvels at night.

The following are four blue light software and hardware filtering solutions you can use to instantly decrease your exposure to blue light emitting technologies at night:

  1. If you use Apple computers (macOS Sierra 10.12.4+) or Apple mobile devices (iOS 9.3+), you can activate a new display setting called Night Shift during your dusk to dawn hours. This setting eliminates much of the blue light from onscreen emissions when activated. After entering your location details, the software will shift your screen colors from bright whites and blues to warm, red hues in accordance to the sun's position in the sky.
  2. If you don’t use an Apple device, you can also download a free program for both desktop and mobile called f.lux. It's almost identical in function to Apple’s Night Shift display setting.
  3. And not to worry if you’re still using an older device that isn't compatible with Night Shift or F.lux, you can also order screen protectors that double as blue light filters.
  4. And if you don’t care about pajama fashion too much and want to go full “biohacker” crazy, you can also purchase blue-blocker glasses to prevent blue light exposure via your eyes while walking around your house at night. However, this goofy eyewear solution isn’t necessary if you set up your living space with my preferred solution....

2. Switch to Red LED Lights After Sunset

With the advent of multi-colored LED technology, illuminating your living space with nothing but crazy red lights once the sun goes down has never been easier...or cheaper.

One of my favorite and most effective methods for lowering blue light exposure after sunset is just to outfitt my night time living spaces with red LEDs. This makes my home look a bit demonic to be sure, but it allows me to keep using lights for cooking, working, reading, writing and relaxing without interfering with my body's natural bedtime and melatonin production.

This usually means purchasing red LEDs for a few fixtures across my kitchen, living room, bedroom and master bathroom to make sure I stay bathed in red light after the Sun goes down.

Having one red LED setup in your bathroom is essential because, whenever you need a bio-break in the middle of the night, you can still turn on a light to make sure your deposit is always “on target”, but don't get jolted awake from an over-eager set of bright vanity lights!

Also, most LED light bulbs and light strips are super cool because they usually come equipped with remote controls and several color setting options. This means that you have the added power to “set the mood” whenever you have parties or special friends over! ;-P


Use LED strip lights to pimp your furniture out to offer more red light around the house.

I used to use this IKEA dresser as a standing desk for a while and usually used the red color option while working.

I could also use the red lights to read with when I went to bed...

...or set the mood with funkier color whenever I had a friend over ;P 

3. Avoid Your Tech At Night Whenever Possible

As a digital nomad, I’ve had to do away with my paper-based books to keep my travel possessions down to a minimum.

This means that, like most people today, my reading happens on screens instead of paper now.

Night time however, is when I get most of my book reading done and I've found that doing so on a bright, iPhone, tablet or laptop just messes with my attempts to fall asleep too much.

If you can’t manage to do your nightly reading on paper under the light of a red LED, it's well worth it to invest in a kindle Paperwhite.

This way you can take your entire e-Library with you wherever you go and eliminate mobile screen intensity blue light.


I strongly advise against getting the tablet-style kindle Fire though. Tablet screens are not ideal for pre-bed reading rituals – with or without blue light filters!

Stick to either the Kindle, Paperwhite, Voyage or Oasis.

The Choice Is Up To You Neo: Red Light or Blue Light at Night?

Now that you know how impactful blue light can be to your long term health at night, can you experiment with some of the tips above to satisfy your insatiable thirst for technology while meeting the important needs of your biology?

Think about the strategies described above like a modern day, high-tech yet hunter-gatherer style campfire.

You can have the best of both worlds – good sleep, circadian hormonal balance and some properly dosed tech after sunset – if you only you can balance the light spectrum right.

Feel free to ask any questions or share your own personal light hacks in the comments below!

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  • Hey Matt,

    Thanks for sharing this post! I’ve been using Flux for some time on my Macbook Air but I wasn’t aware OSX also brought its own native solution.

    Keep it up 🙂

    • Thanks Angel!

      I was super happy to see Apple launch Night Shift for Macs with their recent Sierra OS update. I love f.lux but it tends to slow things down a bit when it kicks in around sunset. Having the native solution really helps to sidestep this performance dip when using your Mac at night.

  • Hi Matt,
    This was very helpful information and could be especially useful for some of my sleep impaired friends and family. Thanks for the healthy tid-bits.

    • Hi KJP,

      I’m glad you found the post so helpful…I’m sure your friends and family will find them useful too! These strategies have been super practical for me to both increase my hours of sleep and improve my quality of sleep.

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