科学家们说亚洲离校生中患有视力问题的人数这几年急剧上升。研究人员在科学杂志《the lancet》上发表报告指出几乎90%的年轻人患有近视—他们认为主要原因是学生们有繁重的功课及没有足够的室外活动而缺乏室外光线。请听bbc英国广播公司科学记者matt mcgrath发回的报道:

the scientists say that young people need up to three hours a day of outdoor light, but many infants are also missing out as they nap during lunch time. dr. ian morgan is the lead author of the study:

i think what's happened in south-east asia is we've got a double whammy. we've got the massive educational pressures and we've got the construction of a child's day in a way that really minimises the amount of time they spend outside in bright light.

the scientists say that genetic factors, long thought to play a big role in short-sightedness, are not as important as the environment. they point to singapore as a place with several distinct ethnic groups, all of whom are now suffering high levels of myopia.

the authors suggest that mandatory time outdoors should be considered by educational authorities across south-east asia as a way of dealing with the problem.