🛑 Weekly Newsletter: John Ott's Classic Book On Light And Human Health

This week, a sneak peak at a very old book on light and health - that's become a classic in the biohacking industry.

Also, our latest articles/videos are added, and some huge discounts that are still available right now.

Still Available: A Sale That You Shouldn't Miss - Maybe The Biggest Up Until Black Friday

Yes, we mentioned this last week as well. But still, this sale is ongoing with a few companies right now. It's Block Blue Ligh and Rouge are still offering huge discounts.

Many of you will ask in our Facebook group about recent discounts, so here we go:

John Ott's Book On Indoor Lighting And Human Health

So this book is a reprint of a book originally published in 1973 and 1976. The title is "Health and Light: The extraordinary Study that Shows How light Affects Your Health and emotional well being."

The book is a bit of a historical artefact and curiosity, but precedes a lot of developments that many consumers and scientists are focusing on in this space today. Grab a copy of the book HERE if you're interested.

John Ott's experiments actually went back to the 1940s. Ott observed that apples won't ripen correctly when you keep them in the box.

Inside the box the apples stayed green and outside they went red. UV light seemed to be a key aspect there, as glass that filters UV would also prevent apples from ripening.

UV light, red, and NIR has huge effects on the plant kingdom. The same is true for visibible light in general (including red), which are fundamental to photosynthesis, the process of turning CO2 and water (H2O) into oxygen (O2).

Timing is important here. Red light at the wrong time of the day, or the presence or absence of UV light, fundamentally changes growth cycles, health, infection risk, ripening/blooming, and many other aspects in plants.

As you already know, light is a biological force that affects growth, health, mood, energy, reproduction, and disease resistance. Natural, full-spectrum sunlight supports biological health in ways that many artificial lighting environments do not. That's true for both plants and humans.

But let's return to Ott's viewpoint on plants and light:

Plants grown under glass, fluorescent lamps, or light lacking parts of the natural solar spectrum behaved differently from those exposed to unfiltered sunlight. From this, Ott proposes that the quality of light matters as much as its brightness. In his view, sunlight contains a balanced range of wavelengths that living systems evolved with, while indoor lighting often distorts or removes important portions of that spectrum.

I've recently covered this topic below - in a study showing fat gain when blue light is present in animals:

Now here's what's shocking about Ott's viewpoint in the 1940s - 1970s.

Many different organisms - whether fish, chickens, mice, and more - are affected in their reproduction, development, behavior, and disease by lighting conditions.

Ott even claims that certain artificial lights, especially some fluorescent lamps, may stress biological systems, while broader-spectrum light is more supportive. He also discusses observations in which filtered light, colored light, and light passing through glass appeared to produce different biological effects.

Again, we've covered the effects of "flicker" in the article below - the "turning on or off" of light often dozens or hundreds of times per second in the past. This is fundamentally unhealthy and stresses the brain, and the reason many people feel worse indoors, such as under LEDs or fluorescent bulbs.

Now let's return to Ott's book:

A major topic of Ott's book is the connection between light and the endocrine system. Ott suggests that the eyes and skin do more than passively receive light - they help regulate internal physiology. This isn't weird, but something we've covered in great detail such as in our sleep article and the 2026 update article/vid.

What's crazy is that this was already known in the 1970s at the latest!

Ott emphasizes the role of light in hormonal rhythms, metabolism, and emotional well-being. This leads Ott to criticize modern indoor life, where people spend most of their time under artificial light and behind windows that block parts of the sun’s spectrum. He also questions the routine use of sunglasses, tinted lenses, and contact lenses, suggesting that reducing natural light exposure to the eyes may have unintended effects.

Rings a bell?

In my opinion, this is precisely one of the reasons why eye conditions are so prevalent - we've moved indoors as humans and no longer get natural light exposure to them. Consider my update on the topic here:

The solution? We can't escape our ancestral past. You need full-spectrum light exposure in your life. And, yes, red and near-infrared light exposure move the needle there, and are a great supplement for most people if they don't get any. But full-spectrum light, including UV, violet, blue, cyan, green, yellow, red, NIR, MIR, and FIR is the original exposure form.

And, no matter your religious background, that's true. If you think the Earth was created 6,000 years ago, we humans still lived outdoors almost all of that ancestry. If you're an atheist or agnostic and believe in evolution, the same is true.

Want to know more about how to do so safely? Of course, check the eye safety article I posted. And check my course, which has a very extensive lecture on UV light exposure (both UVA/UVB!), and Squamous Cell Carcinoma and melanoma, the 2 most dangerous types of skin cancer. I go deep into the science in that course but it's 100% free and contains some content we cannot publish publically.

The moral of the story is simple though, for both Ott and me. Even since the 1970s, we've known that the indoor environment was fundamentally improper for optimal cognitive performance, hormonal health, metabolism, energy production, disease risk, etc, but, indoor lights have only become far worse over that time.

So John Ott warned us back then. And I'm warning you now. As the battle hasn't been won yet, and arguably has become far worse, with incandescent and halogen bulbs replaced everywhere with more unhealthy LED and fluorescent alternatives.

Also, regarding Ott, grab the book HERE if you're curious.

Overall, the thesis of the book Health and Light shows an already great basis in the 1970s on full-spectrum light, photobiology, and light-based health thinking. John Ott's main conclusion that I personally share is that humans, animals, and plants are adapted to natural sunlight, and that replacing sunlight with incomplete artificial light may have consequences for physical and emotional health.

Simple...

But not easy! As the entire society would look different when this is fixed, in the same way, it would look different if we fixed the poor Western diet, or most people's exercise regimens, etc.

Here Are Our Latest Light Therapy Insiders' Articles:

Every single article that we've published recently - you can find the videos in the article itself:

Can Red Light Therapy Replace Sunlight? The Science Explained - Alex's lastest video on why you cannot rely on red light therapy alone and need sunlight for maximum health benefits!
Science Tool: Simplifying Routines, Benefits & Device Selection - A huge primer, by Bart - the red light therapy science tool! Here we simplify the red light therapy benefits, all the articles we've written on the topics, and what the current best devices are for the different goals. As we've got hundreds of articles on the LTI website now, this page should simplify everything big time for you!
June Red Light Therapy News: New Studies, Brain Health & Fat Burning - The latest red light therapy news by the one and only Alex Fergus! New products, science, Q&A, gossip, updates, and everything in between. And as always, some surprises!
Best Red Light Therapy Review & Comparison Content 2026 - Our AI assistant Sally has compiled all of the most important reviews and comparisons for 2026!

Also, Check Out Some Of Our Other Content:

Below you'll find some of our best content that you shouldn't miss:

Light Therapy Advanced Science Course:

Join Bart's 100% free advanced science light therapy course above, where he takes deep dives into many different topics, such as mechanisms, neurology (Alzheimer's, Parkinson's, etc), exercise recovery, skin beauty & rejuvenation, and much more.

Some of the topics are only published in that course, such as UV light risks and benefits, addiction, anxiety, depression, and more. So join HERE!