How Blue Light Affects Your Health

Anita Welch
Apr 9
13 min read

We wake up to our blaring phone alarms; they sleep right next to us all night. Not to mention the fitness trackers with heart rate monitors on our wrists. How else are we supposed to track our sleep?

We immediately check our notifications and apps. Whoops, got stuck scrolling through TikTok for 20 minutes—time to crawl out of bed and flip on the light, dousing ourselves with artificial LED light.

Before we've had a chance to shine real daylight on our eyeballs, we've exposed ourselves to nnEMF (non-native electromagnetic fields) in the form of blue light countless times. And this is the average routine for most people.

The topic of nnEMF is becoming increasingly mainstream, especially with podcast hosts having on guests who talk about light biology and circadian health, like Dr. Jack Kruse (neurosurgeon), Dr. Alex Cowan (PhD researcher), and Zaid Dahhaj (circadian health coach).

But it's still a complex subject that can be pretty difficult to grasp. So, let's talk about it.

What is nnEMF & How Does it Disrupt Your Biology?

Non-native electromagnetic fields (nnEMF) are artificial EMFs generated by modern technology, such as WIFI, smartphones, 5G towers, artificial blue light, etc., as described by experts like Jack Kruse and Alexis Cowan.

For context, native EMFs are natural fields created by sunlight, Earth's Schumann Resonances, and geomagnetic forces that life has evolved to utilize. These native fields help regulate bioelectricity, electron flow, and cellular energy, which nnEMF disrupts the harmony of.

Not only are our bodies constantly polluted by nnEMF wherever we go, from fluorescent lighting in stores to 5G towers every few miles, but we're also dangerously addicted to wireless technology like Bluetooth headphones, fitness trackers, and smartphones.

So, the "in moderation" excuse isn't relevant here.

I'd like to say people are so addicted to them that they're willing to sacrifice their health, but the thing is, I don't think the majority of people actually know the impact nnEMF has on our biology.

According to Dr. Jack Kruse, the biggest issue with nnEMF is blue light because of its disruption of circadian and mitochondrial biology.

However, since blue light doesn't make our heads spontaneously combust as soon as we lay our eyes on it, it's easy to sweep under the rug and go back to doom scrolling and online shopping.

So, I've come here to shed some light (lol😉) on how blue light impacts your health.

Natural vs. Artificial Blue Light: Why the Difference Matters

Light is made up of tiny particles called photons, which travel through space in waves with each having a unique length and strength. The solar spectrum consists of:

Visible light: Red, orange, yellow, blue, green, and violet light are present in roughly equal intensity in direct sunlight. The range shifts throughout the day, for example, more red/orange during sunset. Visible light is what allows us to see during the day.
Infrared light: You feel warmth from the sun due to infrared light, not the visible spectrum.
UV light: Comes in UVA, UVB, and UVC. UVB and UVC are mostly absorbed by the ozone layer, but UVA is what causes tanning and sunburn.

While the sun emits across the entire electromagnetic spectrum, 99% of its energy is in visible, near-infrared, and UV light. Visible light is only about 43%, but it's what our eyes have evolved to detect.

Natural blue light exists within the visible spectrum and is balanced by other wavelengths.

Throughout the day, the balance of these colors varies. In the morning, there's less blue light and more red and infrared, resulting in the colors of the sunrise. Midday consists of more blue light and UV, which is the best time to catch a tan. At sunset, the balance shifts back to higher amounts of red and infrared, giving us the beautiful sunsets we all love to post on Instagram and Snapchat.

Blue light isn't innately harmful; it's actually a primary stimulus of circadian rhythm, and has a positive impact on alertness, mood, and motivation.

When Blue Light Becomes Harmful

To understand the blue light story, you must first know about the suprachiasmatic nucleus (SCN), a cluster of about 10,000 neurons that acts like a clock for the entire body, controlling energy expenditure, appetite, and temperature.

The SCN is directly synced by the light environment.

Retinas are connected to the SCN and are constantly scanning for the brightness and blueness of light. Since blue light helps establish circadian rhythm, when the retinas sense blue light, they signal to the SCN to set the master clock.

In response to the light environment, the SCN generates an oscillation that informs every organ and system within the body about what time of day it is. This is extremely important because different organs and systems activate or prioritize certain jobs depending on what time of the day it is.

For example, your gut is more active and efficient at breaking down food and absorbing nutrients during the day. There are many of these processes that are supported by daytime stimulus, which is signaled by bright light and blue light.

At nighttime, darkness signals to your body that it's time to rest and recover. Your body focuses on essential regenerative processes:

Autophagy: Cells break down damaged or unnecessary parts into reusable building blocks for energy and repair.
Mitophagy: When a mitochondrion is too damaged to be saved, the cell tags it and sends it to be recycled via autophagy.
Apoptosis: Where damaged cells self-destruct, and the remnants are cleaned up by neighboring cells.

In our current state of suboptimal light environments, we aren't getting enough bright, full-spectrum light during the day while getting way too much bright, isolated blue light in general, but especially at night. This creates entropy of the system, which means randomness, chaos, or disorder within our body's systems.

Living in a predominantly indoor environment, we're only experiencing (at most) around 1,000 lux of light, whereas going outside on a sunny day, it's over 100,000 lux. This bright light stimulates the production of serotonin, which can later be converted into melatonin if we're getting dark darkness in the evening.

"Humans evolved under natural sunlight’s full spectrum, but modern, artificial blue light—unbalanced and pulsed—creates 'malillumination,' which is worse than malnutrition." - Jack Kruse

Here is a photo (from BlockBlueLight.com) that illustrates the varying levels of blue light emitted by different light bulbs and their level of melatonin suppression.

Chronic blue light exposure disrupts our circadian rhythm, causes mitochondrial damage, and interferes with hormone production.

Let's talk about how.

What Impact Does Blue Light Have on Human Biology?

I enjoy convenience as much as the next guy, but once I started learning about this stuff, I realized that changing my habits is nonnegotiable to mitigate the health and longevity impacts of constant blue light and nnEMF exposure.

Blue Light Hijacks Dopamine & Lowers Motivation

Jack Kruse frequently talks about blue light's effect on dopamine production. He explains that blue light not only disrupts sleep, but it also hijacks dopamine pathways, lowering levels over time and creating addiction-like behaviors. Ever wonder why gambling is so addictive?

Dopamine is made in the retinas under natural sunlight. Morning sunlight, which is blue light balanced with UVA and infrared, stimulates dopamine production. UV light on the skin then helps regulate and limit excess dopamine.

This natural balance supports motivation, decision-making, and frontal lobe function.

Artificial blue light lacks the full-spectrum, breaking the balance. For example, screens and indoor lighting deliver isolated blue light without the counterbalancing UV or infrared, chronically activating an enzyme (MAO-B) which degrades dopamine. Then, dopamine levels drop in the eyes, frontal lobes, and brainstem.

Lower dopamine desensitizes receptors, making you seek more stimulation. This is why scrolling feels so addictive. People become increasingly compliant, less decisive, and easier to influence.

Blue Light, Mitochondrial Dysfunction, and Cellular Dehydration

The electron transport chain (ETC) is the process by which your body turns food energy into ATP. It's like a conveyor belt in mitochondria that carries electrons (from food) to oxygen, powering your cells like a battery.

Cytochrome c oxidase is the final stop, handing the electrons off to oxygen to make energy and water. Your cells make water! I think this is so neat and kind of crazy that it's not mainstream information?

Anyway, your cells make metabolic water, which is essential for energy transfer, cellular signaling, and waste removal. It helps cells run smoothly to avoid a sluggish metabolism.

It's kind of like in the Wizard of Oz when the Tin Man has to oil himself up. Healthy mitochondria make low-deuterium water that easily conducts a charge; it's low-resistance. When the ETC is delayed, the water quality goes down, creating higher resistance. The whole cell essentially becomes like a rusty, creaking Tin Man (if that makes sense 😅).

Blue light, especially in 400-450nm (the general amount emitted from electronics), is absorbed by heme proteins (essential for electron transfer and energy production) in cytochrome c oxidase, which inhibits the complex's activity and promotes electron leakage (the unintended escape of electrons from their designated pathways) that generates massive reactive oxygen species (ROS) production.

It also impedes the production of metabolic water, leading to cells becoming dehydrated and accumulating deuterium* buildup. High amounts of deuterium can disrupt mitochondrial function, decreasing energy efficiency and spiking harmful byproducts.

*Deuterium is a heavy version of hydrogen, like a heavy backpack that slows reactions.

In the long run, chronic blue light exposure can instigate things like:

Metabolic disorders
Accelerated aging (organ decline, wrinkles, internal wear)
Increased cancer risk
Neurological and cognitive impairments
Apoptosis, necrosis, necroptosis

Blue Light, Digital Eye Strain, & Skin Aging

We feel the effects of blue light on our eyes and skin long before we notice deeper mitochondrial or circadian issues.

Digital Eye Strain (Computer Vision Syndrome)

Spending just two hours on screens can trigger eye strain, fatigue, blurred vision, headaches, and that heavy “tired eyes” feeling.

Jack Kruse links this directly to blue light’s damage in the retina; by inhibiting cytochrome c oxidase in retinal mitochondria, blue light creates excess reactive oxygen species and promotes drusen* buildup near the fovea* in people who are chronically blue-light toxic.

Your retinas are constantly scanning for blue light, but artificial sources overload them without the protective full spectrum of sunlight.

*Drusen are tiny deposits that accumulate as a result of aging. While a few small drusen can be normal, larger and more numerous drusen may indicate an increased risk of age-related macular degeneration (AMD) and can potentially lead to vision loss.

*The fovea is a small pit in the retina of the eye that is responsible for sharp central vision, allowing us to see fine details and colors clearly. It's essential for activities like reading and driving.

Blue Light and Skin Aging (Photoaging)

Blue light penetrates skin and can generate reactive oxygen species directly in skin cells, damage mitochondrial DNA, trigger inflammation, break down collagen, and speed up pigmentation and wrinkles.

Both eye strain and skin aging are early warning signs of the deeper chaos: mitochondrial dysfunction and circadian mismatch. The same morning sunlight and evening darkness strategy that protects dopamine also protects your eyes and skin.

Blue Light Can Lead to Irreversible Hypoxia

Everyone knows that mitochondria are the powerhouses of cells, and they are actually much more than that.

Mitochondria create energy (ATP) through cellular respiration, but they also sense and process electromagnetic signals, including native and nnEMF.

nnEMF overloads this system, causing cells to act as if they are hypoxic (even when they're not), a condition where your body’s tissues don’t get enough oxygen to function properly.

This leads to:

Low NAD+ (a key energy molecule): Can lead to chronic fatigue, brain fog, poor immune function, & difficulty with DNA repair.
Increased reactive oxygen species (ROS): In excess, they can damage DNA, proteins, and lipids.
Oxidative stress: Imbalance of free radicals and antioxidants in the body, leading to cell and tissue damage.
Poor energy production: When the electron transport chain is slowed down, mitochondria don't produce energy at normal rates.

Over time, this contributes to mitochondrial decay, which accelerates aging, neurodegeneration, and disease.

Blue Light Interferes with Circadian Rhythms

Some hormones (like melatonin) are light-sensitive, meaning light exposure influences their production and function. Blue light inhibits the release of melatonin while stimulating cortisol production. Both are circadian biosensors, cortisol being the hormone of daytime and melatonin the hormone of nighttime.

When melatonin production is suppressed, people have trouble sleeping. This disrupts your body's natural diurnal cycles (pattern that repeats every 24 hours due to the Earth's rotation).

Without enough daylight exposure to counter the effects of blue light, circadian rhythms get messed up, leading to poor regeneration, inflammation, and increased risk of disease.

Did you know that shift work is considered a possible carcinogen by the WHO?

According to this PubMed paper, circadian misalignment, especially in shift workers and indoor lifestyles with artificial light, contributes to or worsens many diseases, including:

Impaired alertness and cognition, including diminished attention and memory
Psychosocial disruption, impaired emotional regulation, and increased risk of depression
Negative metabolic impacts
Gastrointestinal disorders
Adverse effects on cardiovascular function and increased risk of heart disease
Impaired immune function
Stroke
Various cancers

Are you convinced yet that light may play a bigger role in our health and well-being than we think?

How to Mitigate Chronic Blue Light Exposure

The issue is two things:

We're suffering from chronic exposure to blue light
We're lacking bright, full-spectrum daylight

The solution: More sunlight and less artificial lighting and screen time.

But how do we achieve this when most of our jobs require that we stare at a computer and spend 8+ hours under fluorescent lighting?

Here’s how you can start reclaiming your light environment.

Get More Sun/Daylight

Jack Kruse's rule of thumb is to see every sunrise. Well, not going to lie, this isn't a realistic option for many people. At least not at first.

I think a good starting point is to prioritize getting daylight on the ole eyeballs within 5-10 minutes of waking every day. Whether it's going for a walk or just sitting outside for 15 minutes, get out there.

As a circadian health researcher, Dr. Alexis Cowan explains, "Natural light in your eyes as soon as possible after waking is essential. It kicks on your metabolism, fatty acid beta oxidation, and ramps up mitochondrial function."

Then, you're going to want to form the habit of going outside more, even if it's only 10-20 minutes at a time. Shoot, even if it's only 5 minutes! If you work from home, take a break every so often to stand outside and stare at some trees or something. These short moments add up throughout the day.

Even on cloudy days, stepping outside for 10 minutes still delivers far more usable light than any indoor bulb.

Pro tip: when you're cruising to work in the morning and back home later in the day, this is a great opportunity to roll down your window or open your sunroof to absorb the daylight.

We need bright full-spectrum light during the day and dark darkness at night to optimize the circadian system. Neither is more important than the other.

Get More Dark Darkness at Night

Alexis Cowan recommends minimising blue light in our homes around sunset (ideally eliminating it, but I know that's tough at first). This means investing in red light bulbs to use in lamps during the evening or using candles instead.

Oftentimes, we can't control our light environment. In this case, blue light glasses come in handy. I'll talk more about these shortly.

Complete darkness is crucial when it's bedtime. That means no T.V., phone screen, or even street light shining through the curtains.

Replace Your Light Bulbs with Full-Spectrum Bulbs or Incandescents

I recently switched out all of our light bulbs with incandescents, and let me tell you, it's a noticeable change. I've noticed much less eye strain, and it creates a more natural-feeling environment, unlike the sterile, hospital feel of LED lighting.

While these bulbs won't replace the need for more sunlight or daylight, they're an essential step toward reducing blue light toxicity in your home.

Blue Light Glasses & Screen Protectors

Our skin detects light through blue light and UV light detectors. So, while blue light glasses are helpful when we can't control our light environments, filtering at the source is ideal.

You can use endogenous filters for electronics, such as F.Lux or Iris, to help protect yourself from isolated blue light. You can also buy plastic covers for T.V. and computer screens.

Not all blue light glasses are good. Honestly, most of them don't block the correct range of light. That's why it's important to buy from a reputable brand. Please don't buy Target blue blockers (🤦🏼‍♀️).

Reputable brands recommended by Dr. Alexis:

These brands actually block the specific 400–550nm range that most disrupts melatonin production.

Prioritize Spending Less Time on Your Phone/Screens

I know this is a super difficult one...but we really have to normalize spending less time on our phones and watching T.V. It is, however, a great opportunity to pick up new hobbies, like crocheting, drawing, painting, reading, writing, playing board games or cards...the options are endless!

What's Next

So, that was a lot. I get it. All of this stuff can be super overwhelming when we have jobs, families, and social lives to worry about.

Start with just one or two of these changes this week — maybe morning sunlight and red bulbs at night — and you’ll likely notice better sleep and more steady energy within days.

Key Takeaways:

Morning sunlight on your eyes within 10-15 minutes of waking is the most powerful way to boost dopamine, metabolism, and set your circadian rhythm.
Artificial blue light from screens hijacks dopamine, creating addictive scrolling and reducing motivation over time.
Blue light at night suppresses melatonin and disrupts mitochondrial function, while true darkness supports repair processes like autophagy.
Chronic blue light causes digital eye strain, accelerates skin aging through collagen breakdown, and contributes to cellular dehydration and oxidative stress.
nnEMF and isolated blue light create “malillumination,” leading to fatigue, inflammation, and higher disease risk.
Small daily changes (more daylight + less evening screens + red bulbs) can noticeably improve sleep, energy, and mood within days.

If this article resonated with you and you’re thinking about how light, circadian health, and mitochondria affect real people’s energy and performance, I’d love to help bring more of this kind of content into the world.

I’m a freelance writer who specializes in clear, science-based health and wellness topics — especially biohacking, fitness, supplements, and mitochondrial health. I help brands communicate complex ideas in a way that’s engaging and actionable for their audience.

Currently open to new projects in the health and fitness space: if you need well-researched blog posts, guides, or educational content on these topics, feel free to reach out via email or DM. Happy to chat about how I can support your brand or business.

References

Chappus, J. (Host). (2025, June 10). Why you should be getting more sunlight, not less | Dr. Alexis Cowan [Video]. YouTube. https://www.youtube.com/watch?v=qxzGOwKXDqY
Chen, E. (1993). Inhibition of cytochrome oxidase and blue-light damage in rat retina. Graefe's Archive for Clinical and Experimental Ophthalmology, 231(7), 416–423. https://doi.org/10.1007/BF00919652
Gulhane, M. (Host). (2023, May 22). Dr Jack Kruse: Deuterium, 4th phase of WATER, & cellular redox [Video]. YouTube. https://www.youtube.com/watch?v=W5w0WainlMM
Holistic Disclosure. (2023, December 18). Blue light kills the fit people | Dr. Jack Kruse | EP 15 [Video]. YouTube. https://www.youtube.com/watch?v=0IjUzKzfIbI
Kruse, J. (2018, August 9). Spending just two consecutive hours on a digital device can cause eyestrain and fatigue [Facebook post]. Facebook.
Kruse, J. (2016, January 7). TIME #6: Is biologic time linked to dopamine levels? JackKruse.com. https://jackkruse.com/time-6-time-and-dopamine/
McNish, H. (2025). The effect of blue light on mitochondria in human dermal fibroblasts. The FASEB Journal, 39(8), Article e70462. https://doi.org/10.1096/fj.202500746R
Schuermann, D., & Mevissen, M. (2021). Manmade electromagnetic fields and oxidative stress—Biological effects and consequences for health. International Journal of Molecular Sciences, 22(7), Article 3772. https://doi.org/10.3390/ijms22073772
Sleep Is A Skill. (2026, March 7). 257: Dr. Melissa Sonners, chiropractor, author/podcaster [Audio podcast episode]. Spotify. https://open.spotify.com/episode/1V4puFB5HS0otNmBVEqquX
Wikström, M. (2018). Oxygen activation and energy conservation by cytochrome c oxidase. Chemical Reviews, 118(5), 2469–2490. https://doi.org/10.1021/acs.chemrev.7b00664