In This Article
New Science on the Mind-Body Benefits of Red Light
We all enjoy the glory of a bright red and orange sunrise, and now science is just beginning to understand the therapeutic impact red light has on the body. Find out why watching the sunrise is so important for your health!
In a 2021 study published in the journal Scientific Reports, researchers found that gazing for just three minutes a week at a red-light LED flashlight (calibrated to at 670nm) helped restore more youthful vision.
After the age of 40, our eyes begin to age more rapidly than any other of our other organs. In fact, over your lifetime, you may see a 70 precent reduction in retinal mitochondrial energy production. The retinal cells of the eye are vulnerable to age-related decline, but looking at red light boosted mitochondrial energy function of the color sensors in study subjects’ eyes, producing a 17 percent improvement in vision for all 24 study participants.
The most interesting finding in this study was that the benefits of red-light therapy were only seen when the therapy was administered between 8 and 9 a.m. When study subjects looked at red light in the afternoon, there was no change in the mitochondrial function of the eyes—suggesting a circadian switch may be involved. Let’s find out why but first a quick review of the visual light spectrum.
The Spectrum of Light at Sunrise
The electromagnetic spectrum includes all the frequencies generated by the sun. In order from the highest to the lowest frequencies, we have: gamma rays, x-rays, ultraviolet radiation, visible light (violet, blue, green, yellow, orange, and red), infrared radiation, microwaves, and radio waves. While all of the sun’s radiation affects our health, deep red light at the end of the visual light spectrum is emerging as an important activator against the threat of aging.
Red light that borders the infrared spectrum has the lowest frequency (slow waves) in the visual light spectrum. Violet and blue light, which border the ultraviolet spectrum, have the highest frequency (fast waves). Because blue light has a higher frequency, it produces more energy and heat than lower-frequency red light.
During sunrise and sunset, the sun is lower in the sky and the sun’s rays penetrate the Earth’s atmosphere at an angle. Rays hitting Earth from low on the horizon scatter the high-frequency blue light, while low-frequency red light remains intact. This is why we see more red and less blue during sunrise and sunset. The blue sky we see during the day around noon is a result of the easily-scattered nature of higher-frequency blue light.
To summarize, blue light from the sun is often more diffuse, less penetrating, and less heating, while red and infrared light are more direct and heating.
During the sunrise and sunset, damaging ultraviolet (UV) rays are also blocked since they have higher frequencies, similar to blue light. (One study discovered that when your shadow is taller than you while you stand, then you are getting the optimal exposure to red and infrared light while being protected from UV radiation.)
Get Back to Natural Circadian Rhythms
At sunrise and sunset, with blue light more scattered, or filtered by the atmosphere, there is an abundance of uninterrupted red light that we evolved to depend on. As the Scientific Reports study on retinal health and red light showed, just three minutes of gazing at focused red light boosted retinal mitochondrial energy production and vision for up to a week.
Getting the same effect from nature is ours for the taking if we just get up and experience the sunrise. At sunrise, the sun is much easier to look at and, in fact, it’s hard not to bath in its glory.
Gazing at artificial infrared and red light, on the other hand, does come with a warning. The Scientific Reports study used a simple flashlight calibrated to 670 nm as the source of red light. Most of these are cheap and often also deliver infrared light along with the red light. Long-term studies link gazing at infrared light to retinal damage and cataracts. Keep your gaze to three minutes or less. This minimal amount of infrared light can be rejuvenating for the eyes and body, but too much can be harmful. Until the research has been fully vetted, I suggest keeping your eyes healthy by getting your morning dose of deep red light by watching the sunrise.
I emphasize sunrise, and not sunset, because of the study findings on timing being important, and because infrared light is naturally greater in the morning. At sunset, there is more dust in the air, which may interfere with soaking up red light. This may also explain why, in the study, the body did not respond to red light therapy in the afternoon.
Also, infrared light exposure in the morning is designed to prep and protect your skin from damaging UV rays that peak around midday.
Our ancestors spent their days outside with direct exposure to the full spectrum of the sun’s solar energy. Our bodies are now maladapted because we spend the majority of our lives inside.
To reset your daily circadian rhythms, make watching sunrise a sacred ritual, taking a moment of gratitude while bathing in nature’s healing rays.