How Does Light Impact Sleep?

The body’s wake and sleep cycles are influenced by the circadian rhythm, the internal body clock that regulates our activities and behaviors. Sun exposure in the morning signals the body to restart the wake-sleep cycle. Sunlight, and some other types of short-wavelength light, inhibits the production of melatonin, a hormone that makes us sleepy. Morning light signals the body that it’s time to re-start the sleep-wake cycle. Melatonin production decreases, and it’s then that we become our most alert. When the sun sets, melatonin production increases and signals our bodies that it’s time to prepare for sleep.

When these circadian rhythms are disrupted, it often prevents us from falling asleep at night. For children as well as adults, later bedtimes often mean we are sleepy during the day.

The mission of the National Sleep Foundation (NSF) is to improve health and well-being through sleep education and advocacy. With the help of the National Science Teachers Association, the Bright Schools Competition will also give students the opportunity to receive a positive and enduring Science Technology Engineering and Math (STEM) experience.

More information on sleep requirements and sleep cycles:
How Much Sleep Do We Really Need?
Melatonin & Sleep
Sleep-Wake Cycle: Its Physiology and Impact on Health