Eyesight Rejuvenation: Yet another reason to go outside in the mornings

Deep red light reverses the effect of ageing in the human eye - but only in the morning

There is something special about sunlight in the mornings. Now new research is telling us that the time of day you spend outside in daylight is critical.

Regular outdoor exposure to natural unfiltered full-spectrum daylight provides clear health benefits even on cloudy overcast days. Large scale studies with thousands of people show that lifespan is increased by years, depression and anxiety are substantially reduced and cardiovascular disease is minimized, as compared to people who spend most of their time indoors¹.

But does the time of day that you are exposed to daylight matter?

Outdoor morning daylight is rich in the blue needed to synchronize circadian clocks and the red needed to restore eyesight in the aging eye. But afternoon daylight is not as effective. Insufficient amounts of these crucial wavelengths are found in artificial LED light designed to meet US Department of Energy standards

Resetting Circadian Clocks

We have long known that blue-rich morning daylight corrects the drift of circadian clocks to later hours caused by evening blue-rich LED light exposure. A morning dose of bright blue rich daylight in the 460-490 nm segment of the light spectrum is a highly potent synchronizer of circadian clocks. Exposure to daylight later in the day, however, does not have the same effect.

Boosting Vision in the Ageing Eye

Now, there is another reason to favor morning daylight outdoors. Deep red light at about 670 nm boosts vision, reversing the effects of ageing on the human eye. But this red light treatment is only effective in the morning and doesn’t work later in the day².

Red light and invisible near-infrared in the range 650 - 1000 nm penetrate beneath the skin and boost mitochondrial energy production. Mitochondria are the tiny batteries inside the cells of the body that synthesize the ATP (adenosine triphosphate) chemical energy that powers metabolism. As we age ATP energy production drops off, especially in the retina of the eye which has the highest usage of energy and concentration of mitochondria³.

Exposing the photoreceptors in the eye to red light revs up the mitichondria energy production and corrects the degradation of vision that begins at about age 40.

This is part of the much broader health-boosting effects of red and infrared which will discuss in another Substack post.

Reducing Body Fat and Appetite

Bright blue-rich morning light is also effective in reducing body fat and appetite in obese women⁴. Conversely blue rich light in the evening boosts appetite and promotes weight gain. This is yet one more example of why the timing of light exposure matters.

Failure of Our Modern LED lights

When lighting is regulated to promote cheap white brightness, measured by Lumens/Watt (the intensity of green and yellow wavelengths produced per watt of elcctricity) , you get a very distorted artificial light.

As the chart above shows, LEDs that are designed to meet the Department of Energy (DOE) new 125 lumens per watt standard, which goes into effect in 2028, are deficient in 460 - 490 nm blue and also in 670 nm red and infrared. In other words staying indoors under such deficient LED lighting cannot in any way replace the benefits of natural outdoor daylight.

Campaign for Healthy Lighting

I urge you to join the campaign to protect healthy lighting and indicate that you are willing to sign a petition to reverse the harmful DOE 125 lumens per watt rule which is scheduled to go into effect in 2028.

For more remarkable insights into what we have done to ourselves by moving indoors and switching on narrow spectrum blue-rich LED lights, see my book THE LIGHT DOCTOR.

Sources

1. Moore-Ede M (2024) THE LIGHT DOCTOR: Using Light to Boost Health, Improve Sleep and Live Longer. CIRCADIAN Books. https://www.amazon.com/Light-Doctor-Martin-Moore-Ede/dp/B0D54SHWS4

2. Shinhmar H, Hogg C, Neveu M, Jeffery G. Weeklong improved colour contrasts sensitivity after single 670 nm exposures associated with enhanced mitochondrial function. Sci Rep. 2021 Nov 24;11(1):22872. doi: 10.1038/s41598-021-02311-1. PMID: 34819619.

3. Fosbury R and Jeffrey G (2024) Light-life interactions beyond photosynthesis. https://herschelsociety.org.uk/wp-content/uploads/2024/02/The-Astrophysics-of-Earth_v3.3.pdf

4. Danilenko et al (2013) Bright Light for Weight Loss: Results of a Controlled Crossover Trial. Obes Facts 6:28–38 DOI: 10.1159/000348549