Turn Off The Light: Electric Light Disturbs Natural Sleep Patterns

Feeling tired this morning? Blame it on Thomas Edison. The technological marvel of electricity has brightened our lives, perhaps a little too much, wrote Charles Czeisler, Ph.D., professor of sleep medicine at Harvard Medical School, in a Nature article. The use of electric lights at night disturbs natural sleep patterns, or circadian rhythms, and can cause people to consume caffeine to stay awake far later than they should, he said.

The eye not only lets us see, but also serves a set of secondary functions like responding to light and resetting the circadian clock. When the eyes are exposed to artificial light between the hours of sunset and sunrise, that light inhibits neurons that promote sleep and suppresses the release of a hormone called melatonin, which helps put people to sleep, Czeisler said.

The use of artificial light has likely also delayed the so-called second wind people feel in the late afternoon that gives them energy to finish the day. "Before the widespread use of electric light, people probably experienced that second wind in the mid-afternoon, keeping them going until night fell," said Czeisler. "But light exposure after sunset signals 'daytime' to the [brain], shifting the clock later, postponing the second wind and delaying the onset of melatonin secretion. As a result, many people are still checking e-mail, doing homework or watching TV at midnight, with hardly a clue that it is the middle of the solar night." Read full article at Christie Rizx...

Author of the article: 
Christie Rizx
Medical Daily