Light and Human Biology
How Electromagnetic Radiation Regulates Electrons, Water, and Cellular Function
Kendall Toerner
Published: February 23, 2026
Before food, before supplements, before fitness routines… there is light.
Not metaphorical light.
Not “good vibes.”
Light as physics — electromagnetic energy interacting with electrons inside your cells.
Your body is not just biochemical, it is electrical.
And light is one of the primary forces shaping that electrical system.
What Light Actually Is
Light is electromagnetic radiation.
It travels as oscillating electric and magnetic fields. Each wavelength carries a specific amount of energy.
The visible colors you see — red, orange, yellow, green, blue, violet — are only a small portion of the full spectrum.
Beyond red is infrared.
Beyond violet is ultraviolet.
You cannot see them.
Your biology still responds to them.
Light Is Not Just “Brightness”
Natural sunlight is not a single color.
It is a continuous blend of billions of wavelengths delivered at once. And that blend changes constantly:
- Morning light is richer in infrared
- Midday light includes ultraviolet
- Evening light shifts toward red again
- Seasons change UV intensity
- Latitude changes spectral strength
This daily and seasonal rhythm acts as a biological timing system.
Indoor light does not do this.
Most artificial lighting:
- Emits narrow spikes of certain wavelengths
- Contains very little infrared
- Contains almost no ultraviolet
- Does not change throughout the day
- Is dramatically lower in intensity
Your biology evolved under dynamic, broadband sunlight — not static indoor bulbs.
Why Infrared Matters (Even Though You Can’t See It)
Infrared light sits just beyond visible red.
It penetrates deeper into tissue than visible light and interacts with:
- Mitochondria (your energy-producing structures)
- Blood flow
- Water inside cells
- Cytochrome enzymes in the electron transport chain
Research shows near-infrared light can influence mitochondrial respiration and ATP production by interacting with cytochrome c oxidase.
Sunrise and sunset are especially rich in infrared.
Modern indoor environments contain very little of it.
Why Ultraviolet Matters
Ultraviolet (UV) light sits beyond violet.
It carries more energy per photon and drives:
- Vitamin D production
- Nitric oxide release (affecting blood flow)
- Melanin production
- DNA repair signaling
- Redox adjustments in the skin
UV is angle-dependent and seasonal.
Glass blocks most UVB. That means indoor life removes one of the key signals your skin evolved to receive.
Your Body Is Built to Absorb Light
You are not just a passive object in sunlight.
Your cells contain molecules specifically designed to interact with photons.
These are called chromophores.
Porphyrins
Porphyrins are part of heme molecules in your blood and mitochondria.
They absorb specific wavelengths and help regulate electron flow inside the energy systems of your cells.
Melanin
Melanin is not just pigment.
It absorbs across ultraviolet, visible, and infrared wavelengths. It helps buffer oxidative stress and regulate how photon energy is distributed in tissue.
It is a biological light-management system.
DHA (in Your Retina and Brain)
Docosahexaenoic acid (DHA) is a fatty acid heavily concentrated in your retina.
Its structure makes it highly responsive to light-driven signaling. Your retina is not just a camera — it is neural tissue optimized for photon detection.
Light Sets Your Internal Clock
You have specialized photoreceptors that do not form images.
They measure environmental light to regulate timing.
Melanopsin-containing retinal cells respond strongly to blue wavelengths and send signals directly to your brain’s master clock.
This regulates:
- Cortisol timing
- Melatonin suppression
- Sleep-wake cycles
- Metabolism
- Hormone coordination
Neuropsin (OPN5) is sensitive to near-UV wavelengths and plays a role in circadian and seasonal entrainment.
Light tells your body what time it is.
Not your phone.
Not your calendar.
Light.
Light and Energy Production
At the smallest level, light interacts with electrons.
When photons are absorbed:
- Electrons shift energy states
- Redox balance changes
- Mitochondrial signaling adjusts
- Reactive oxygen species act as signals
- Gene expression can shift
Cells are redox systems embedded in water.
Electromagnetic radiation influences that system directly.
This is why light exposure affects:
- Sleep
- Mood
- Metabolism
- Energy levels
- Hormonal rhythms
Not because it is symbolic.
Because it is physical.
Why Indoor Light Is Different
Artificial light is engineered for visibility, not biology.
It:
- Lacks ultraviolet
- Contains minimal infrared
- Emits discontinuous spectral spikes
- Stays constant all day
- Is far dimmer than natural outdoor light
Outdoor sunlight can exceed 100,000 lux.
Most indoor environments are below 500 lux.
That is not a small difference.
It is a different electromagnetic environment.
And biology responds accordingly.
First Principles Summary
- Light is electromagnetic energy interacting with electrons in your cells.
- The visible spectrum is only a small portion of what biology detects.
- Infrared and ultraviolet are invisible but biologically active.
- Sunlight is broadband and constantly changing.
- Artificial light is narrow, static, and incomplete.
- Your mitochondria, skin, retina, and circadian system evolved under the full solar spectrum.
Health is not only about what you eat.
It is also about the electromagnetic environment you live in.
Because life is not just chemistry.
It is organized light interacting with water and electrons.
References
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- Hamblin MR.
- Pollack GH et al.
- Oancea E et al.
- Berson DM et al.
- Buhr ED et al.
- Slominski A et al.
- Stillwell W, Wassall SR.
- Brainard GC et al.
- Reinhold MI et al.
Mitochondrial signaling in mammalian cells activated by red and near-IR radiation.
Photochemistry and Photobiology, 2008.
PMID: 18047459
(Near-infrared interaction with cytochrome c oxidase and mitochondria)
Photobiomodulation and mitochondrial mechanisms.
AIMS Biophysics, 2017.
PMID: 28507427
(Mechanisms of red/near-IR light on cellular respiration)
Light-induced expansion of exclusion zone water.
Langmuir, 2013.
PMID: 23895326
(Infrared effects on structured water)
UVA-induced nitric oxide release from skin.
J Invest Dermatol, 2013.
PMID: 23348519
(UVA and vascular signaling)
Phototransduction by retinal ganglion cells that set the circadian clock.
Science, 2002.
PMID: 12060680
(Discovery of melanopsin photoreception)
Neuropsin (OPN5) mediates UV light detection in mammals.
Current Biology, 2015.
PMID: 25660537
(Near-UV circadian sensing)
Melanin and melanogenesis in photoprotection and redox biology.
Physiol Rev, 2004.
PMID: 14715915
(Melanin as a redox-active photoreactive system)
Docosahexaenoic acid and photoreceptor membrane function.
Chem Phys Lipids, 2003.
PMID: 12686133
(DHA in retinal biophysics)
Action spectrum for melatonin regulation in humans.
J Neurosci, 2001.
PMID: 11160465
(Wavelength-specific circadian effects)
Porphyrin photochemistry and biological electron transfer.
Photochem Photobiol Sci, 2010.
PMID: 20458366
(Porphyrins as biological chromophores)
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