Summary
Highlights
Upon waking, artificial light from phones is insufficient to trigger cortisol spikes for alertness. Getting outside to view natural sunlight, even on cloudy days, is crucial for optimizing daily focus and nighttime sleep. Look towards the sun but avoid direct painful staring, and do not wear sunglasses during this time. Corrective lenses are acceptable.
This practice is backed by extensive scientific research, showing significant positive impacts on wakefulness and sleep. If you wake before sunrise, use artificial lights indoors, but once the sun is out, venture outside. Artificial lights are not bright enough to replace natural sunlight for the morning cortisol spike, but they can disrupt sleep if used too late at night.
The duration of sunlight exposure needed varies based on weather. On a clear day, aim for about 5 minutes. On a cloudy day, target 10 minutes. For densely overcast or rainy days, extend to 20-30 minutes. Crucially, do not attempt to get this exposure through a car windshield or a window, as it significantly reduces efficacy. Always try to get outside.