增加户外活动可减少近视风险

 　　WASHINGTON, Sept. 15 (Xinhua) -- Spending more time outdoors may reduce the risk of developing nearsightedness in children, a Chinese study said Tuesday.

　　The study, published in the Journal of the American Medical Association, looked at about 1,800 children in grade one from 12 primary schools in Guangzhou, China.

　　About half of the students were assigned to one additional 40-minute class of outdoor activities, which was added to each school day, and their parents were encouraged to engage their children in outdoor activities after school hours, especially during weekends and holidays.

　　The other half children and their parents continued their usual pattern of activity.

　　More time outdoors may cut kids risk of nearsightedness: <a href=http://www.hxen.com target=_blank class=infotextkey>study</a>

　　At the end of the three-year study, 30.4 percent of children who spent more time outdoors were nearsighted, compared to 39.5 percent of those in the control group.

　　"Our study provided the highest level of evidence for myopia prevention and control that outdoor activities, as a simple public health intervention¹, may significantly reduce the rate of myopia without affecting the schoolwork," lead author He Mingguang, professor of Sun Yat-sen University, told Xinhua.

　　He said an addition of two-hour daily outdoor activities may help achieve the goal of controlling the occurrence of myopia, commonly known as nearsightedness.

　　The researchers called the results "clinically important" because small children who develop myopia early are most likely to progress to high myopia.

　　"Thus a delay in the onset² of myopia in young children, who tend to have a higher rate of progression, could provide disproportionate long-term eye health benefits," they wrote in the paper.

　　In an accompanying editorial, Michael Repka of the Johns Hopkins University School of Medicine said establishing the long-term effect of additional outdoor activities on the development and progression of myopia is "particularly important" because the intervention is "essentially³ free and may have other health benefits."

1 intervention   

n.介入，干涉，干预

参考例句：

• The government's intervention in this dispute will not help.政府对这场争论的干预不会起作用。
• Many people felt he would be hostile to the idea of foreign intervention.许多人觉得他会反对外来干预。

2 onset   

n.进攻，袭击，开始，突然开始

参考例句：

• The drug must be taken from the onset of the infection.这种药必须在感染的最初期就开始服用。
• Our troops withstood the onset of the enemy.我们的部队抵挡住了敌人的进攻。

3 essentially   

adv.本质上，实质上，基本上

参考例句：

• Really great men are essentially modest.真正的伟人大都很谦虚。
• She is an essentially selfish person.她本质上是个自私自利的人。