How Light Exposure Affects Your Sleep Schedule

Every cell in your body runs on a roughly 24-hour clock. This internal clock, or circadian rhythm, determines when you feel most alert and productive and when it’s time to hit the hay. While these rhythms are baked into our genes, there’s also a powerful reset button: light. Once upon a time, that meant the sun. But today, with increased access to artificial light, we have a bit more control over our internal clocks and can shift our sleep cycles away from the natural daylight schedule.

Scripting by Chia-Yi Hou.

Editorial Production by Tristan Rivera and Juliet M. Beverly.

Scientific Review by Ryan Logan.