Children who spend more time outdoors may have a lower risk of becoming nearsighted，new research suggests.

In the study，researchers looked at about 1，900 schoolchildren. The scientists found that the kids who had been instructed to spend more time outdoors for three years were 23 percent less likely to develop nearsightedness during this time than those who had not been instructed.

The researchers selected six schools and required the children，whose average age was 7 at the start of the study，to attend one additional 60-minute class of outdoor activities during each school day for three years. The parents of these children were also encouraged to join their children for outdoor activities after school，especially during weekends and holidays. The other children，from another six schools，continued their usual activity patterns. After three years，30.4 percent of the kids in the intervention(干预) group became nearsighted，compared with 38.5 percent of the kids in the other group.

It is not clear exactly why spending more time outside would benefit children’s eyesight，the researchers said. However，some research has suggested that the higher levels of light intensity found outdoors may increase the release of the chemical dopamine（多巴胺）of the eye. In turn，dopamine is known to restrain（抑制）the type of growth in the eye that is associated with nearsightedness.

Based on the new results，the researchers recommend that children spend more time outdoors because of the potential benefits to their eyesight. However，it's important to protect kids' skin and eyes from UV light，which can be damaging.

Baths and bathing have long been considered of medical importance to man. In Greece there are the ruins(废墟) of a water system(系统) for baths built over 3,000 years ago. The Romans had warm public baths. In some baths, as many 3,000 persons could bathe at the same time.

Treating disease by taking bathing has been popular for centuries. Modern medical bathing first became popular in Europe and by the late 1700’s has also become popular in the United States.

For many years frequent(经常的) bathing was believed to be bad for one’s health. Ordinary bathing just to keep clean was avoided(避免), and perfume was often used to cover up body smells!

By the 1700’s doctors began to say that soap and water were good for health. They believed that it was good for people to be clean. Slowly, people began to bathe more frequently. During the Victorian Age of the late 19th century, taking a bath on Saturday night became common.

In the United States ordinary bathing was slow to become popular. During the 18th and early 19th centuries, many Americans were known as “The Great Unwashed!” In one American city , for example, a person was only allowed to take a bathe every thirty days! That was a law!

Frequency of bathing today is partly a matter of habit. People know that bathing for cleanliness is important to health, Doctors know that dirty bodies increase the chance of diseases. As a result, in the United States, people generally bathe often. Some people bath once a day at least. They consider a daily bath essential (=necessary) to good health.

Everyone on this earth (well, the majority) enjoys hot showers. They make us feel cozy and relax us when we need it most. 【小题1】 Find out what can happen if you shower with cold water every day below.

Take a cold shower, and your immune system will be affected. Indeed, our body considers the temperature of the cold shower as an attack. 【小题2】 Their role is to protect us from various attacks including infections due to viruses. Therefore, our immune system will be better boosted. In short, a daily cold shower therefore helps to fight against possible infections.

【小题3】 More exactly, when we sleep, our body temperature drops slightly. In this sense, if you take a cold shower before going to bed, you will quickly find sleep and improve, at the same time, the quality of your sleep. On the contrary, a hot shower increases the body temperature and promotes arousal (唤醒) a little more.

Cold water also benefits the skin. The more you take a cold shower, the firmer, smoother and more elastic your skin will be. 【小题4】   All in all, taking a cold shower regularly will improve the tone of your skin. Basically, if you want to remain young longer, take a cold shower every day!

Finally, a good cold shower every day also helps burn fat. If you want to lose weight, then make a cold shower your best friend. When you take a cold shower, your body will seek to warm itself by producing more heat and burning energy. However, if you want to lose weight, you have to combine a cold shower with a workout. 【小题5】