Screentime before bedtime may leave people feeling groggy in the morning. Cell phones, computers and TVs emit blue light. And exposure to that bluish light during the two hours before bed can keep us from getting a good night’s rest, a new study finds.
It cut down the number of minutes people slept. It also left them feeling groggy in the morning.
It’s been known for quite a while that “blue light is bad for sleep,” observes Shadab Rahman. He was not involved in the new study. His work sleep at Brigham and Women’s Hospital in Boston, Mass., does, however, study how light affects the body’s internal “clock.” Its natural cycles tell us when to sleep and when to get up in the morning. These cycles are known as our circadian (Sur-KAY-dee-un) rhythms. The light of day and the dark of night both work to help keep this internal clock running on a roughly 24-hour cycle.
Computers, televisions, tablets and other electronic devices give off all colours of light. And, he notes, evidence has been emerging that these screens — and especially the blue light they give off — can disrupt the body’s clock. Data show that this blue light tends to make us more alert at night. That makes it harder to fall asleep get all the rest we need.
Source: Science News for Students