Morning light exposure is a simple yet powerful tool for optimizing health and well-being. Dr. Andrew Huberman, a neurobiology and ophthalmology professor at Stanford University, has extensively discussed the benefits of this practice. This article explores the science behind morning light exposure and provides practical tips on how to incorporate it into your daily routine.
Morning light exposure is deeply rooted in our physiology. Numerous peer-reviewed studies have shown that exposure to light early in the day is the most potent stimulus for wakefulness and positively impacts sleep quality at night [1]. This mechanism involves the stimulation of melanopsin intrinsically photosensitive ganglion cells in our eyes, which trigger a cascade of events, including a spike in cortisol, our body's main stress hormone, helping us feel alert and focused [2].
To practice morning light exposure, step outside within the first hour of waking and expose your eyes to natural light. Keep the following points in mind:
Never stare directly at the sun, especially when the sunlight is too intense. Direct and prolonged exposure to intense light can cause significant damage to the eye's retina, leading to conditions like solar retinopathy [3].
For this specific practice, avoid wearing sunglasses, as they can block the necessary light required to stimulate your eyes properly. However, eyeglasses or contact lenses with UV protection are acceptable, as they typically don't hinder the beneficial light frequencies needed for optimal eye stimulation.
The ideal duration for sunlight exposure varies depending on weather conditions:
The longer duration on overcast or rainy days compensates for the significantly reduced light intensity.
Get your sunlight exposure outdoors whenever possible. Attempting to gain this exposure through a window or a car windshield can significantly reduce its effectiveness, as most modern glass types are designed to block certain ultraviolet (UV) light rays, which are part of the light spectrum necessary to trigger the beneficial mechanisms in the eyes [4].
If you wake up before the sun rises, you can turn on artificial lights in your home to help you wake up. However, once the sun is up, it's crucial to get outside and expose your eyes to natural sunlight, as artificial lights in your home are not bright enough to stimulate the necessary physiological responses.
Conversely, at night, even a small amount of artificial light can disrupt your sleep. This asymmetry in our biology means that early in the day, we need a lot of light, but at night, even a little artificial light can disrupt our sleep [5].
Morning light exposure is a simple and effective tool for enhancing wakefulness during the day and improving sleep quality at night. By understanding the science behind it and incorporating it into your daily routine, you can harness the power of this natural and free resource for better health and well-being.
Some light is better than none; turn on your bright artificial indoor lights until you can make it outside for natural sunlight exposure.
There will still be plenty of sunlight available, however, it'll be less intense, and you'll want to stay in it for 20-30 minutes to compensate.
While lamps that simulate natural sunlight are a good substitute, nothing beats natural morning light.
Aiming for 10-20 minutes of exposure is good in most cases, however, this changes depending on weather, geographic location, and the individual.
Ideally, you want to catch the sun within an hour of it rising, as the levels of blue light, which are key for circadian rhythm regulation, are at their highest [6].