"View sunlight within minutes of waking daily Stanford neuroscientist Andrew Huberman explains that light-sensing neurons in the eye (melanopsin ganglion cells) must receive early-morning sunlight to correctly time cortisol and melatonin release across the entire day. He states that viewing sunlight through a window is "50 times less effective" than going outside, and that even 2–10 minutes of outdoor morning light on a consistent basis is enough to anchor the circadian clock. Someone who shifts from scrolling a phone indoors at wake-up to stepping outside for a few minutes will find it easier to fall asleep at a regular time and wake feeling more rested. Source: Andrew Huberman, Huberman Lab, Master Your Sleep & Be More Alert When Awake"