A German physician and light researcher just published a paper that stopped us in our tracks. Not because it surprised us — but because it perfectly explained something we felt while building the Helder 2.
Who is Dr. Alexander Wunsch?
Dr. Alexander Wunsch, MD, PhD is one of the most respected voices in photobiology — the science of how light affects living things. Based in Germany, he has spent decades studying what light actually does to the human body: not just to our eyes, but to our hormones, our cells, our sleep, and our mood.
He's published extensively on the biological effects of artificial lighting, lectured at Wismar University in architectural lighting design, and has been a vocal critic of the EU's decision to phase out incandescent bulbs. He's testified on the health risks of modern LED lighting and advocated for what he calls "salutogenic lighting" — light that actively supports health rather than undermining it.
He's not selling a device. He doesn't have a product. He just follows the science, wherever it leads.
His latest paper, published in LED Professional Review (September 2025), is called "Incandescent LEDs and Their Hidden Health Power." And it puts words to something we've believed since day one at AriHelder.
We replaced fire with the wrong kind of light.
For almost all of human history, after the sun went down, our light source was fire. Candles. Torches. Fireplaces. And for millions of years before that, our ancestors lived under forest canopies where light filtering through leaves had a very specific character: rich in deep red and near-infrared wavelengths, low in harsh blue light.
Our bodies adapted to that spectrum. Not just our eyes — every cell, every hormone system, every repair mechanism we have evolved alongside that particular mix of light.
Then, in the space of about 30 years, we replaced almost every light source in modern life with LEDs. And the most common LEDs today are heavy in blue light, and almost completely stripped of the deep red and near-infrared that natural light always contained.
"Modern phosphor-converted LEDs cut off above 630–700 nm due to efficiency-driven design, creating a chronic near-infrared deficit for those mostly sitting indoors."
— Dr. Alexander Wunsch, LED Professional Review, 2025
In plain language: the lights above your desk, in your office, in most hospitals and schools — they deliver the stimulating, stressful part of the light spectrum and leave out the restorative part. Every day. All day.
What near-infrared actually does inside you.
Near-infrared light — the invisible wavelengths just beyond red — passes through your skin. That's not a marketing claim, it's physics. And once it reaches your tissue, it does something remarkable: it activates the parts of your cells responsible for producing energy.
Every cell in your body contains tiny power plants called mitochondria. They run on a molecule called ATP — the body's energy currency. Near-infrared light, particularly around 850nm, is absorbed by an enzyme in those mitochondria called cytochrome c oxidase. When that enzyme absorbs NIR light, it produces more ATP. More energy for the cell. Better circulation. Less inflammation. Faster repair.
Wunsch identifies three core effects:
- More cellular energy. NIR activates mitochondria to produce more ATP — the fuel every cell runs on.
- Better circulation. Improved microcirculation means oxygen and nutrients reach tissue more efficiently.
- Less oxidative stress. NIR counteracts the cellular damage caused by blue-heavy light and the stresses of daily life.
This is not new knowledge. Researchers have studied photobiomodulation — the science of light affecting cellular function — for decades. What Wunsch adds is the evolutionary context: your body doesn't just tolerate NIR light, it expects it. It's been calibrated for it since long before we existed as a species.
Blue light isn't evil. But we're getting too much of it, at the wrong times.
Wunsch is careful here, and we think it's worth being careful too. Blue light isn't the villain. In the morning, it helps set your internal clock. It boosts alertness. It tells your body it's daytime. That's useful and normal.
The problem is dose and timing. When you're bathed in blue-dominant light all day — and well into the evening — your stress hormone system stays activated. Cortisol stays elevated. Melatonin gets suppressed. Your body never fully receives the signal to shift into repair mode.
And crucially, without compensatory NIR, there's nothing counteracting the oxidative stress that blue light causes in your eyes and skin. Natural sunlight always delivered both. Modern indoor lighting delivers the blue, strips out the NIR, and leaves your biology with an equation that doesn't balance.
Consider the numbers:
- In natural sunlight, near-infrared makes up 40% or more of total radiant energy.
- In a standard white LED, near-infrared output is effectively zero.
- In the Helder 2, 88% of total optical output is NIR at 856nm — independently verified by OHSP instrument.
Why this matters for what we're building.
When Arjen designed the Helder 2, the wavelength choice wasn't arbitrary. 856nm NIR and 631nm deep red are both in the biological sweet spot — deep enough to penetrate tissue, specific enough to interact with the mitochondrial pathways that matter. The device delivers a concentrated dose of exactly the wavelengths Wunsch identifies as missing from modern life.
We don't say the Helder 2 treats anything. We never will. But Wunsch's paper articulates clearly why this kind of light belongs in a daily wellness routine — not because it's medicine, but because it's what your biology was designed for and is no longer getting from its environment.
He writes that the physiological benefit of NIR-rich light is "a byproduct of spectral quality, not a targeted medical intervention." We couldn't have said it better. The Helder 2 isn't trying to cure you of anything. It's giving your cells back something they lost when we all moved indoors under fluorescent tubes and blue-shifted LEDs.
Our approach
We publish our verified specs. We share science from researchers we respect, like Dr. Wunsch. We let real users share their real experiences. We don't make promises about what light will do for your specific body — because nobody honestly can.
What we can say is this: the Helder 2 delivers 10.47 watts of independently verified red and NIR output, measured by OHSP instrument, at wavelengths your mitochondria recognise. What happens after that is between you and your cells.
No claims. Just light. Lots of it.