The History of Light Therapy

From ancient Rome to Nobel Prizes, NASA to lasers, Light Therapy has a colorful history.

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The Ancients

Gods, Light, and Solariums

Throughout human history, the consistent connections of ‘light’ and ‘healing’ can't be ignored.

Ancient Chinese medicine emphasizes the importance of light in health, and how this invisible flow of energy powers our body.

The Egyptian goddess of healing, Sekhmet, is the daughter of the Sun God, Ra.

The Greek & Roman God of Healing, Apollo, is more famously the God of Light.

The son of Apollo, Asclepius, is the greek god of treatment. In fact, even today, the ‘Rod of Asclepius’ is a universally recognized symbol of medicine.

These connections did not just exist in mythology and literature, they were born of the observable ability of light to heal bodies. If you were to visit a Roman hospital 2000 years ago you’d be met with an intriguing sight:

Huge panels of red glass, filtering sunlight, streaming into hospitals and healing patients suffering from ‘diseases of withering’. The ancients called these specialized rooms Solariums.

Today we recognize Solariums as civilization’s first implementation of Photomedicine.


Niels Ryberg Finsen

The Father of Phototherapy

In 1896, Niels Finsen cured Smallpox with Red Light Therapy. Smallpox. A highly contagious viral-respiratory disease with no cure, according to the World Health Organization.

He continued to demonstrate groundbreaking healing effects of phototherapy, proving that light therapy could be used to cure Smallpox, Lupus Vulgaris, and by logical extension, hundreds of other ‘diseases of civilization’. His work rattled the medical world, rightfully earning him the Nobel Prize in Medicine in 1903 for “opening a new avenue of medical science."

Tragically, Finsen died shortly after winning the Nobel Prize and his crucial discovery of light as a medicine fell into darkness.

In the last few years of his life, Finsen was committed to making light therapy accessible to every human being, not just for curing diseases, but as a requirement for daily health.

He writes; “Nevertheless, I believe implicitly that in the future use will be made of this new therapeutic agent [Light], and the proof experiment once made, it will be easy to carry it out practically under the form of Light Baths; and lastly, to determine whether they are to be blue, violet, or red, the variations in their strength and duration, and whether natural or artificial.” - Finsen, Phototherapy, 1896

Now, 125 years later, we are picking up where the Father of Photomedicine left off. Making light bathing accessible to every human being in the world.

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NASA & Phototherapy

A New Frontier of Medicine

NASA accidentally rediscovers phototherapy while exploring plant growth in deep space.

The National Aeronautics and Space Administration, NASA, began experimenting with Light emitting diodes, LEDs, to grow plants in space. To the delight of the astronauts, they found the plants readily grew with the energy from these small ‘artificial suns’, even in space.

But what was more remarkable was what happened to the astronauts themselves. They reported a surprising improvement in bone mass, atrophied muscles, and wound healing; symptoms that commonly plague humans in a zero-gravity environment. A press release followed; “NASA scientists have found that cells exposed to near-infrared light from LEDs, which is energy just outside the visible range, grow 150 to 200 percent faster than cells not stimulated by such light.”

This ‘new’ finding kicked-off the modern era of photomedicine, using light to heal and improve bodies. However, LEDs in this era of technology were extremely expensive and inefficient. As a result, photomedicine was reserved for hospitals, medical practices, and research institutions.

It would take several more decades before LED light therapy would be available to the masses.

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Phototherapy with LEDs


LED Breakthroughs make Phototherapy Scalable

In the last decades, LED technology has progressed so rapidly that phototherapy is now accessible to individuals, not just hospitals.

Just like the exponential growth of computer processing power, LEDs become ~200x better every decade (see Haitz Law). A device that would cost $20,000 in 2000, would cost just $100 for the same overall performance just 10 years later. This incredible advancement in light efficiency has sent shockwaves across the world.

We have seen light therapy become commonplace in hospitals and medical practitioners' offices all across the world. Beginning in 2010, red light devices, infrared saunas, and laser pain relief have become key parts of the modern doctor's toolbox.

Yet, even with the overwhelming positive effects of light therapy, its practice has been relegated primarily to medical professionals. and expensive individual treatments.

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Smart Light Therapy


Automated light therapy software and hardware

Today, in 2021, we are living in the most exciting period of the Photomedical Revolution.

With Sunflower, Light therapy is now controlled by software to perfectly tune the output to emulate clinically-tested outputs. We built Sunflower to connect you directly to the vast scientific insights to continuously improve light therapy.

Light is a safe and effective treatment for hundreds of diseases, because light is a necessary requirement for human health, like food, water, and oxygen.

Now, 125 years after the world was blessed with Finsen’s brilliance, photomedicine is becoming mainstream.

Today, our team at JustLight is focused on making light therapy accessible. We work hard every day to build the vision of Niels Finsen, a Light Bath in every home. Because until we do, there is vast preventable suffering in our world.

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Let's Learn about Light!

At JustLight, we are committed to furthering the public understanding of the health necessity of light.

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