近视正在不停的蔓延，近视可以避免吗？

China has been gripped by an unprecedented rise in myopia, also known as short-sightedness. Sixty years ago, 10–20% of the Chinese population was short-sighted. Today, up to 90% of teenagers and young adults are. Other parts of the world have also seen a dramatic increase in the condition, which now affects around half of young adults in the United States and Europe  Because the eye grows throughout childhood, myopia generally develops in school-age children and adolescents.

近视眼的发病率在中国处于一种前所未有的上升阶段。六十年前，中国人口的10-20％是近视的。如今，高达90％的青少年和年轻人几乎都近视。世界其他地区的近视比例也大幅增加，已经影响了美国和欧洲大约一半的年轻人。由于眼睛在儿童时期处于发育阶段，近视普遍发生在学龄儿童和青少年之中。

For many years, the scientific consensus held that myopia was largely down to genes and Gene-finding efforts have now linked more than 100 regions of the genome to short-sightedness. But it was obvious that genes could not be the whole story. Genetic changes happen too slowly to explain this rapid change — or the soaring rates in myopia that have since been documented all over the world. There must be an environmental effect that has caused the generational difference,” 

多年来，科学共识认为近视在很大程度上归因于基因，基因研究工作现已将基因组的100多个区域与近视相关联。但很明显，基因遗传不可能是所有的原因。遗传变化发生得太慢以至于无法解释这一快速变化 - 近年来，全球记录的近视率高涨，必然有环境的影响，造成代际差异。

There was one obvious culprit: book work. The modern rise in myopia mirrored a trend for children in many countries to spend more time engaged in reading, studying or — more recently — glued to computer and smartphone screens.  The average 15-year-old in Shanghai now spends 14 hours per week on homework, compared with 5 hours in the United Kingdom and 6 hours in the United States. Researchers have consistently documented a strong association between measures of education and the prevalence of myopia.  

有一个明显的罪魁祸首就是太多的书面工作。现代近视率的高涨反映了许多国家的孩子们花了大把的时间在阅读和学习上，或者是在电脑和智能手机的屏幕上。

在上海，平均15岁的孩子，现在每周花在做作业上的时间是14小时，而在英国则为5小时，而在美国则为6小时。研究人员一直在记录教育与近视患病率之间的强烈联系。

However, after studying more than 4,000 children at Sydney primary and secondary schools for three years, researchers found that children who spent less time outside were at greater risk of developing myopia.  Close work might still have some effect, but what seemed to matter most was the eye's exposure to bright light. The leading hypothesis is that light stimulates the release of dopamine in the retina, and this neurotransmitter in turn blocks the elongation of the eye during development. Researchers now suspect that under dim (typically indoor) lighting, the cycle is disrupted, with consequences for eye growth. 

然而，在研究了4000多名悉尼中小学的孩子学习了三年后，研究人员发现在户外度过较少时间的儿童近视发病的风险较大。繁重的课业可能仍然有一些影响，但最重要的原因似乎是眼睛暴露在明亮的光下的时间长短。主要的假设是光刺激视网膜中多巴胺的释放，而这种神经递质又在发育过程中阻止了眼球的延长。研究人员现在怀疑在昏暗（通常是室内）照明下，这个周期是中断的，对眼睛的发育是有影响的。

Based on epidemiological studies, Ian Morgan, a myopia researcher at the Australian National University in Canberra, estimates that children need to spend around three hours per day under light levels of at least 10,000 lux (someone under a shady tree, wearing sunglasses, on a bright summer day)  to be protected against myopia. He recognizes that many schools do not have the flexibility to add time outdoors. So last year, in collaboration with Congdon, he began piloting the idea of teaching kids in a classroom made of glass to let in more natural light.

根据流行病学研究，澳大利亚堪培拉国立大学近视研究员伊恩·摩根（Ian Morgan）估计，儿童每天需要花费大约三个小时时间在阳光下可以保护视力不近视，光照至少为10,000勒克斯（也就是一个人在阳光明媚的夏天，在阴凉的树下，戴着太阳镜）。他认识到许多学校没有灵活性的增加户外活动的时间。所以去年，他与康登合作，开始尝试在玻璃教室里给孩子上课，让更多自然的光能够进入教室中。

In some places, children cannot get any more outdoor light: there are too few hours of daylight, the sun is too fierce, or the cold too intense. Animal research¹⁰ has suggested that powerful indoor lights could do the trick instead: light boxes currently sold to treat seasonal affective disorder, for example, can deliver up to 10,000 lux illumination, but their effects on myopia have not been tested extensively in humans

在某些地方，孩子们无法得到更多的户外照明：有的地方有阳光的时间很短，有的阳光很猛烈或者太寒冷。动物研究建议，强大的室内灯可以做代替：例如，目前出售的用于治疗季节性情感障碍的灯箱可以提供高达10,000勒克斯光照，但是它们对近视的影响尚未在人体中广泛测试。

Meanwhile, researchers have been working on ways to prevent myopia from worsening. Sankaridurg and her colleagues have developed special glasses and contact lenses that can alter eye growth by focusing light from distant images across the entire field of view, rather than just at the centre, as standard lenses do. Other research groups have shown that nightly eye drops with a neurotransmitter-blocking drug called atropine can also help to control myopia progression¹⁴, although the mechanism remains unclear. “

同时，研究人员一直致力于防止近视眼的恶化。 Sankaridurg和她的同事开发了专门的眼镜和隐形眼镜，可以通过将远距离图像的光聚焦在整个视野而不仅仅在眼睛的中心，从而改变眼球的生长。其他研究组已经表明，夜间滴眼药水和一个称为阿托品的神经递质的阻断药物也可以帮助控制近视的发展，尽管该机制尚不清楚。

But eye drops and light boxes do not have quite the appeal of sending children outside to play, which has plenty of other benefits besides those for the eyes. “It probably also increases physical activity, which decreases likelihood of obesity and enhances mood,” Rose says. “I can only see it as a win — and it's free.”

但眼药水和灯箱，相对于带孩子去户外运动来说并不具有吸引力，他们除了对眼睛有好处外，没有其他好处。 “但是户外运动可以增加身体的活动，从而降低肥胖的可能性并改善心情。”Rose说，“我肯定选择户外运动 - 而且它是免费的。”

Euroeyes has examined and treated patient with myopia for many years in Europe. In Germany we are centre of Myopie correction and prevention. We  have been following the development of progression of myopia among children for many years.

德视佳眼科已经在欧洲多年监测和治疗近视患者。在德国，我们是近视矫正和预防中心。我们多年来一直在跟踪儿童近视的发展。