Just like the body needs food to maintain a daily supply of nutrients, the eyes need fresh morning sunlight to function efficiently. Behind them, eyes hide a thin layer of nerve tissue called the retina which contains zillions and zillions of photoreceptor cells. When the eyes are deprived of these photons that come from the sunlight, it affects the retina’s ability to use energy from light to regulate the circadian rhythms of the body, and hence, overall health. Emphasizing how light is so important for human bodies, Stanford neuroscientist, Dr. Andrew Huberman (@HubermanLabClips) uploaded a short clip from an episode of his popular Huberman Lab podcast. In the clip, he calls the morning sunlight a “foundational power tool” for health.
“I wake up in the morning and I want to reach for my phone,” says Huberman in the 2022 clip. “but I know that even if I were to crank up the brightness on that phone screen, it’s not bright enough to trigger that cortisol spike, and for me to be at my most alert and focused throughout the day and optimize my sleep at night. So what I do is that I get out of bed, and I go outside.”
Huberman goes on to explain that even though each day is different and each day has different amounts of sunlight, getting outside is the most important thing. If it’s a bright, clear day, and the Sun is at a low angle in the sky, it’s the perfect time to have a quick sunbath. If there’s cloud cover and the sun is not visible, then it becomes especially important to get out in the Sun because the body needs extra energy from light around this time.
Another helpful point that Huberman churns out about the “morning sunlight viewing” process is the intensity with which one should gaze at the Sun. “If it’s a very clear day, I do not need to stare directly into the Sun,” he suggests, “If it’s very low in the sky, I might do that, because it’s not going to be very painful to my eyes. However, if the Sun is a little bit brighter and a little bit higher in the sky, sometimes it could be painful to look at.”
The crux, he says, is to not look at any light, sunlight or otherwise, if it appears too bright or painful to the eyes. But as far as the morning sunlight is concerned, it’s best to not look at it through a car’s windshield, a window, or even sunglasses. It’s however, okay to wear contact lenses or eyeglasses. “So try and get outside, ideally in the first five minutes of waking, or maybe it’s 15 minutes, but certainly within the first hour after waking,” explains the neuroscientist.
Proceeding further in the podcast, Huberman explains that this thing about morning sunlight viewing is not some “biology woo-woo,” but rather a solid concept grounded in the core of human physiology. Early morning light viewing, he said, is the “most powerful stimulus for wakefulness throughout the day and it has a powerful, positive impact on your ability to fall and stay asleep at night.”
What if someone wakes up before the Sun is out? Huberman recommends turning on artificial lights in the home environment. However, as soon as the Sun is out, one should go out and soak up its light.
Although the light seeping from artificial lights can’t replace sunlight, it is bright enough to “disrupt your sleep if you look at them late at night.” Studies have revealed that “the effect of morning light is that it ‘advances’ the clock, while evening and night light ‘delays’ the clock.” So spending too much time under artificial lights and too little under the Sun can be harmful to health. Plus, lack of sunlight can also lead to mood disorders, depression, social withdrawals, and psychological conditions like these.
Huberman details how much time one needs to remain under the sunlight on different types of days. On clear days, for example, one usually needs light exposure for about five to seven minutes. On cloudy days, it can be about ten minutes, given the lower intensity of the Sun. And on days when the sky is dark and rainy, Huberman recommends at least twenty to thirty minutes of exposure to trigger the cortisol as well as other bodily mechanisms. Ultimately, it’s the body’s retina that processes and distributes the light energy to govern the 24-hour clock. Receiving it from a natural source ensures that eyes have as much spectral diet as they need to function efficiently.
