Most evenings, before watching late-night comedy or reading emails on his phone, Matt Nicoletti puts on a pair of orange-colored glasses that he bought for $8 off the Internet.

大多数晚上，马特·尼科莱蒂(Matt Nicoletti)会在看深夜喜剧或用手机阅读电子邮件之前戴上他花8美元在网上买的橙色眼镜。

“My girlfriend thinks I look ridiculous in them,” he said. But Mr. Nicoletti, a 30-year-old hospitality consultant¹ in Denver, insists that the glasses, which can block certain wavelengths² of light emitted by electronic screens, make it easier to sleep.

30岁的尼科莱蒂是丹佛市的一名酒店预订专员。“女朋友觉得我戴着这眼镜的样子很可笑，”他说。但他坚持认为，它可以阻挡从电子屏幕发出的特定波长的光线，使人更容易入睡。

Studies have shown that such light, especially from the blue part of the spectrum³, inhibits⁴ the body’s production of melatonin, a hormone⁵ that helps people fall asleep. Options are growing for blocking blue light, though experts caution that few have been adequately tested for effectiveness and the best solution remains⁶ avoiding brightly lit electronics at night.

研究表明，此类光线（尤其是光谱的蓝色部分）可抑制人体制造褪黑素——一种可帮助人们入睡的激素。众多阻挡蓝光的产品应运而生，但专家警告说，几乎没几种产品的有效性经过了充分的测试验证，目前的最佳解决方案仍是避免在晚上接受来自电子屏幕的亮光。

A Swiss study of 13 teenage boys, published in August in The Journal of Adolescent Health, showed that when the boys donned orange-tinted glasses, also known as blue blockers and shown to prevent melatonin suppression, in the evening for a week, they felt “significantly more sleepy” than when they wore clear glasses. The boys looked at their screens, as teenagers tend to do, for at least a few hours on average before going to bed, and were monitored in the lab.

8月，《青少年健康期刊》(The Journal of Adolescent Health)上发表了一项来自瑞士的研究。这项涉及13名十几岁男孩的研究显示，受试者们在一周期间每晚佩戴橙色眼镜（又称为蓝光阻隔眼镜），可防止褪黑素抑制效应，他们比佩戴透明眼镜时“明显更有睡意”。这些男孩在实验室内接受了监测，他们像普通青少年一样，每晚睡觉前平均会看上几个小时的电子屏幕。

Older adults may be less affected⁷ by blue light, experts say, since the yellowing of the lens and other changes in the aging eye filter out increasing amounts of blue light. But blue light remains a problem for most people, and an earlier study of 20 adults ages 18 to 68 found that those who wore amber-tinted glasses for three hours before bed improved their sleep quality considerably⁸ relative to a control group that wore yellow-tinted lenses, which blocked only ultraviolet light.

专家还说，由于衰老而产生的晶状体泛黄和其他变化会过滤过量的蓝光，老年人或许不那么受蓝光的影响。但对于大多数人来说，蓝光依然是个麻烦。此前的一项涉及20名18至68岁成年人的研究发现，睡前三小时佩戴琥珀色眼镜者的睡眠质量大大优于佩戴只阻隔紫外线的黄色隐形眼镜的对照组。

Devices such as smartphones and tablets are often illuminated⁹ by light-emitting diodes, or LEDs, that tend to emit more blue light than incandescent¹⁰ products. Televisions with LED backlighting are another source of blue light, though because they are typically viewed from much farther away than small screens like phones, they may have less of an effect, said Debra Skene, a professor of neuroendocrinology at the University of Surrey in England.

智能手机和平板电脑等设备通常使用发光二极管，即LED照明，它们发出的蓝光往往多于白炽产品。英国南安普顿大学的神经内分泌学教授德布拉·斯基恩(Debra Skene)指出，带LED背光的电视机是蓝光的另一个来源，但它们的观看距离一般比手机之类的小屏幕远得多，对人体的影响应该比较小。

LEDs are also increasingly popular as room lights, but “warm white” bulbs, with less blue, tend to be a better choice than “cool white” for nighttime use. The lighting¹¹ company Philips also makes a bulb, called Hue¹², that can change the intensity¹³ of its component¹⁴ colors via an app, and GE last month announced a reduced-blue LED bulb, meant to be used before bedtime.“Conceptually, anything that will decrease that blue light exposure at night will be helpful,” said Christopher Colwell, a neuroscientist at the University of California, Los Angeles. “I know some gamers who swear by those orange-tinted goggles¹⁵.”

LED在室内照明上也越来越受欢迎，但是如果单以夜间使用而论，蓝光较少的“暖白色”灯泡其实是比“冷白色”光源更好的选择。照明公司飞利浦生产了一种叫做Hue的灯泡，可以通过应用程序改变其发光谱中各种颜色的强度。通用电气上个月也发布了一款低蓝光LED灯泡，以供睡前使用。“从概念上讲，任何可降低夜间蓝光暴露的东西都会有所助益，”加州大学洛杉矶分校的神经科学家克里斯托弗·科尔韦尔(Christopher Colwell)说。“我知道有些游戏玩家对橙色护目镜推崇备至。”

But orange glasses are not a panacea¹⁶, Dr. Skene said. “It isn’t just get rid of the blue and everything’s fine,” she said. The intensity of light, in addition to color, can affect sleep, she said, and not all brands of orange-tinted glasses have undergone enough independent testing for their ability to aid sleep.

但橙色眼镜也不是万能的，斯基恩博士说。“屏蔽蓝光并不能解决所有问题。”除了颜色，光的强度也会影响睡眠，她说，而且，也不是所有品牌的橙色眼镜都接受过足够的独立测试来证实其确实有能力辅助睡眠。

Screens that are not backlit, such as some e-book readers, are preferable to typical brightly lit screens, Dr. Skene said.

斯基恩博士表示，非背光的屏幕——如某些电子书阅读器——要比常见的明亮屏幕更可取。

Mr. Nicoletti says that the orange glasses he wears, an industrial-safety brand called Uvex, do make some colors, notably¹⁷ blues¹⁸ and greens, harder to distinguish. He also uses applications designed to alter the blue light impact of his devices depending on the time of day: an app called f.lux for his computer and Twilight¹⁹ for his mobile phone.

尼科莱蒂说，他的橙色眼镜出自工业安全品牌优唯斯(Uvex)，在佩戴该眼镜后，他确实感到难以分辨某些颜色，其中又以蓝色和绿色最为明显。他还使用了可根据一天中的不同时间改变设备蓝光影响的应用：名为f.lux的app用于电脑，名为Twilight的app用于智能手机。

Other ideas are proliferating²⁰. An Ohio company called LowBlueLights.com, for example, offers filters said to block blue light by covering the screens of electronic devices like the iPhone or iPad. Other company products include “low blue” LED lights and orange eyewear.

其他主意也在不断涌现。例如，俄亥俄州的一家名为LowBlueLights.com的公司提供了可覆盖在iPhone或iPad电子设备屏幕上的滤膜来阻挡蓝光。其他公司的产品有“低蓝光”LED灯和橙色眼镜等。

During the daytime, experts say, exposure to blue light is good. Best of all is sunlight, which contains many different wavelengths of light. “That’s what our brain knows,” said Kenneth P. Wright Jr., director of the sleep and chronobiology lab at the University of Colorado, Boulder²¹.

专家称，在白天，蓝光暴露还是很不错的。最好的光源就是阳光，它包含许多不同波长的光。科罗拉多大学波尔得分校睡眠与生物钟实验室的主任小肯尼思·P·赖特(Kenneth P. Wright Jr.)博士说：“我们的大脑很清楚这一点。”

A 2013 study he led, published in the journal Current Biology, showed just how different things can be without nighttime lights: After participants had camped in the mountains for a week, their bodies began to prepare for sleep about two hours earlier than normal.

他在2013年领导的一项研究发表在《当代生物学》杂志(Current Biology)上，该研究显示了没有夜间灯光可以造成多大的改变：在山中露营一周后，参与者的身体比平常提前了两个小时开始准备进入睡眠状态。

Short of cutting out all evening electronics, experts say, it’s advisable to use a small screen rather than a large one; dim the screen and keep it as far away from the eyes as possible; and reduce the amount of time spent reading the device.

专家建议，如果不能完全避免在晚上使用电子产品，那么最好使用小屏幕而不是大的；请降低屏幕的亮度，并让它离眼睛越远越好；减少从电子设备上阅读信息的时间。

“If you can look at the iPhone for 10 minutes rather than three hours, that makes a lot of difference,” Dr. Skene said.

“如果你能把看iPhone的时间从三小时减少到10分钟，可是能带来很大改变的，”斯基恩博士说。