THE NEED FOR SLEEP
Why do we need to sleep?
For thousands of years, humans have asked the question: “Why do we sleep?” and modernscientists are still trying to find the answer. But one thing we do know is that it’s good for our physical and mental health. Physically, sleep helps prevent sickness and keeps our body healthy. Mentally, we study and work better when we sleep for about eight hours the previous night. Sleep mightalso stop dementia when you are older.
A twenty-first-century problem
In this century, lack of sleep is becoming a big problem. The average American sleeps less than seven hours a night —that’s two hours less than a century ago. Our modern,
24-hour-day lifestyle means that more and more of
us are working at different times of the day—and night. We often stay up late into the night, and some of us even work all night and sleep during the day. This is a problem because our body’s natural clock is connected with the movement of the sun. In other words, if we don’t sleep at night for long periods, it can be bad for our health.
The problem of lights and screens
But perhaps the biggest problem for sleep comes from electric lights and screens. Modern cities use bright LED lights through the night, which changes the way we sleep. In
addition, the screens of our computers, tablets, and smartphones all send out blue light.
The bluer and brighter the light, the more difficult it is to get tired and go to sleep. As a result, some medical experts now suggest that we shouldn’t watch more than two hours of television per day and that we should stop looking at screens (including phones) one hour before we go to bed. But since light and screens are so important in our lives, how many of us will take this advice?
