高度概括一下：用眼过度，造成近视眼。我从小就知道看书xx分钟需要休息、眺望远处。但是，知道和做到完完全全是两回事。我父母不戴近视眼镜。所以，按照遗传学，我应该不会近视。但是，我是。尤其是现在，如果我用眼过度（在手机上看书、报），晚饭后出门散步，明显感觉视觉模糊。所以，我开始“听书”，保护视力。效果不错。

儿童近视度数飙升背后的故事

The story behind soaring myopia among kids

https://www.npr.org/2023/10/17/1200611635/the-story-behind-soaring-myopia-among-children

世界卫生组织警告说，到2030年，世界上40%的人口将患有近视。 仅在美国，近视率在过去 50 年里就飙升，从 1971 年的 25% 上升到 2017 年的近 42%。其中许多近视病例是儿童，他们近视的年龄越来越小。 在中国，他们专门追踪早发性近视，目前超过 80% 的青少年和年轻人都是近视。

关于为什么这么多孩子近视的问题长期以来一直存在争议，因为过去视力不佳仅归因于遗传。 现在，专家们一致认为，由于孩子们花费大部分时间的方式发生了变化，正在发生其他事情。 外出时间太少。 呆在室内的时间太多，经常盯着屏幕。

对于眼睛仍在发育的幼儿来说，这些习惯会导致他们的眼睛优先考虑近视力而不是远视力。 反过来，他们的眼球开始拉长，引发近视。

加州大学伯克利分校临床验光副教授玛丽亚·刘（Maria Liu）博士说：“我们谈论的是四、五岁的儿童会变得近视。”

孩子近视越来越早

Harmony Yu七岁时，她的远视力变得模糊。 她读了很多书——每天大约 200 页——花在近距离查看页面上的文字上的所有时间导致她患上了近视。

Harmony Yu的母亲蔡庆非常重视女儿的诊断结果。 “当她被诊断出患有近视时，我和我的丈夫都度过了一个不眠之夜，因为她太年轻了，我们知道情况会变得多么糟糕，”蔡告诉美国国家公共广播电台。

早发性近视会导致晚年出现危险的视力问题，包括视网膜脱离、青光眼、白内障，甚至完全失明。

但Harmony Yu的案例并非个例。 她是玛丽亚·刘博士位于加州大学伯克利分校的近视控制诊所寻求治疗的 1700 名患者之一，该诊所是美国第一家此类诊所。

减缓儿童近视加深的探索

尽管许多同事持怀疑态度，刘医生还是于 2013 年开设了这家诊所。

“学校临床方面认为近视是纯粹的遗传问题，”刘说。 “他们甚至不相信近视控制是一回事。”

但刘医生不久前在中国做眼科住院医师期间曾遇到过一种治疗方法。 这是一种特殊类型的隐形眼镜，称为角膜塑形镜或ortho-k，被证明可以减缓儿童近视的进展。 这些是过夜佩戴的硬性隐形眼镜，有点像佩戴牙齿保持器，可以将患者的眼球重塑回健康的球形，同时有可能矫正他们的视力。

这不是一种新的治疗方法，也不适合所有人，但刘医生开始给她诊所的许多患者开这种药，其中包括 Harmony Yu。

“我的视力从相当模糊，看不清远处的物体，变得非常清晰，颜色也更清晰，尤其是在更远的区域，” Harmony Yu说。 “我对此感到非常高兴。我实际上可以看到东西，而无需花费太多精力或在鼻子上戴上很厚的眼镜。”

预防儿童近视

刘医生解释说，预防儿童早发性近视的最佳方法是限制屏幕时间，并尽可能让他们到户外玩耍。 “他们需要玩真正的玩具，”刘说。 “他们需要参与真正的户外生活。”

这个建议也适用于成年人。 刘博士建议定期进行户外休息，扫视地平线3-5分钟，以锻炼我们的远视力。 她指出，在持续长时间的近距离工作后，这些休息是最有效的，而且阳光本身也能高度预防近视。 还有一个进一步的警告——看向窗外或环视一个大的室内空间并不算数。 刘说，当我们在室内时，我们的眼睛可以感觉到墙壁和天花板，这会拥挤我们的余光。 因此，充分进行户外活动是关键。

因此，下次当你发现自己盯着屏幕几个小时时，请尽力休息一下并呼吸新鲜空气。眺望远处，尝试发现树上的鸟儿或天空中的飞机。 从长远来看，你的眼睛会感谢你的。

The World Health Organization warns that by 2030, 40% of the world's population will be nearsighted. In the U.S. alone, myopia rates have soaredover the past 50 years, from 25% in 1971 to nearly 42% in 2017. Many of these myopia cases are in children—who are going nearsighted at increasingly younger ages. In China, where they specifically track early onset myopia, over 80% of teens and young adults are now nearsighted. 

There's been a longstanding debate over why so many kids are going nearsighted—because bad eyesight used to be attributed solely to genetics. Now, experts agree that something else is going on, resulting from a shift in how children spend the majority of their time. Too little time outside. Too much time indoors, often staring at screens.

For a young child whose eyes are still developing, these habits cause their eyes to prioritize near vision rather than distance vision. In turn, their eyeballs begin to elongate, triggering nearsightedness.

"We're talking about [children who are] age four or five years old becoming myopic," said Dr. Maria Liu, an associate professor of clinical optometry at The University of California, Berkeley.

Kids are developing myopia earlier and earlier

Harmony Yu was seven years old when her distance vision became blurry. She had been reading a lot—roughly 200 pages a day—and all that time spent looking at text close up on the page had caused her to develop myopia.

Yu's mother, Qing Cai, took her daughter's diagnosis very seriously. "When she was diagnosed with myopia, my husband and I both went through a sleepless night because she was so [young] and we knew how bad it can get," Cai told NPR.

Early onset myopia can lead to dangerous vision problems later in life, including retinal detachment, glaucoma, cataracts, and even complete loss of vision. 

But Harmony's case is not unique. She's one of 1700 patients seeking treatment at Dr. Maria Liu's Myopia Control Clinic – the first of its kind in the U.S. – at the University of California, Berkeley.

A quest to slow down the progression of myopia in children

Dr. Liu opened the clinic in 2013, despite skepticism from many of her colleagues.

"The clinical side of the school considered myopia a pure genetic problem," said Liu. "They didn't even believe myopia control was a thing."

But Dr. Liu had come across a treatment some time ago in China, during her ophthalmology residency. It was a special type of contact lenses called orthokeratology, or ortho-k, shown to slow down the progression of myopia in children. These are hard contact lenses that are worn overnight—kind of like wearing a retainer for teeth—that can reshape the patient's eyeballs back to a healthy spherical shape while potentially correcting their vision.

This is not a new treatment, and it's not right for everyone, but Dr. Liu began prescribing it to many of her patients at her clinic, including Harmony Yu.

"My vision went from pretty blurry, couldn't see distant objects, to really sharp, and color was clearer, especially in farther areas," said Yu. "I was really happy about that. I can actually see things without having to spend too much effort or having really thick glasses on my nose." 

Preventing myopia in children

Dr. Liu explained that the best way to protect children against early onset myopia is to limit screen time and get them playing outside as much as possible. "They need to play with real toys," Liu said. "They need to engage in real outdoor life."

This advice goes for adults, too. Dr. Liu suggests taking regular outdoor breaks to scan the horizon for 3-5 minutes in order to exercise our distance vision. She notes that these breaks are most effective after a sustained amount of near work, and that sunlight itself is highly protective against myopia as well. And one further caveat – looking out the window or looking around a large indoor space doesn't count. Our eyes can sense the walls and ceiling when we are indoors, which crowds our peripheral vision, according to Liu. Thus, getting fully outdoors is key.

So, next time you find yourself staring at a screen for hours, try your best to take a break and get some fresh air. Look into the far distance, try to spot some birds in the trees or planes in the sky. Your eyes will thank you in the long run.

This story was written by Katie Monteleone and edited by Amanda Orr. It is part of Body Electric — NPR's 6-part series exploring the relationship between technology and the human body.

Follow along with the whole series here. Talk to us on Instagram@ManoushZ, and on Facebook @tedradiohour, or record a voice memo and email it to us at BodyElectric@npr.org.

Body Electric was produced by Katie Monteleone and edited by Sanaz Meshkinpour with production support from Rachel Faulkner White.

Original music by David Herman. Our audio engineer was Valentina Rodríguez Sánchez. Our fact checker was Chloee Weiner.