Today most people do not get enough sleep. The Centres for Disease Control and Prevention (CDC) has called insufficient sleep an epidemic. While we are finally paying attention to the importance of sleep, the need for dark is still mostly ignored.
That’s right. Dark. Your body needs it too.
Being exposed to regular patterns of light and dark regulates our circadian rhythm. Disruption of this rhythm may increase the risk of developing some health conditions including obesity, diabetes and breast cancer. (WATCH: Not getting eight hours of sleep? Here’s how to fake it. Post continues after the video.)
Light regulates our sleep and wake patterns.
The physiological processes that control the daily cycle of sleep and wake, hunger, activity levels, body temperature, melatonin level in the blood, and many other physiological traits are called the endogenous circadian rhythm.
On its own, the endogenous circadian rhythm is nearly, but not exactly, 24 hours. Our bodies rely on the Sun to reset this cycle and keep it at precisely 24 hours, the length of our days. The light – and the dark – are important signals for the cycle. This circadian rhythm has developed over three billion years as life evolved on Earth in the context of the Sun’s day/night cycle. It is built deeply into our genetic makeup. (Post continues after the gallery.)