FOR ELECTRONIC DEVICES LIKE LAPTOPS, phones, anything with a LED or LCD display, the problem is that they produce a large amount of artificial blue light. Our natural cue to what time of day it is, primarily to know when morning is, is blue light. By exposing ourselves to large amounts of blue light late at night, we are giving our bodies a cue that it’s time actually to wake up instead of go to sleep. This can lead to defects in our circadian rhythm, and it’s been shown that when we have our biological clock out of phase with the natural day-night cycle outside, that can lead to increases in the rates of diabetes, cancer, heart disease, and even depression.

对于任何像笔记本和手机这样带有LED或LCD屏幕的电子设备来说，问题就在于它们会发出大量人造蓝光。我们自身对一天中各时间段的感知就依靠蓝光，其中主要是知道什么时候是早上。深夜我们还把自己暴露在大量蓝光下，就是在提示身体该起床了，而不是该睡觉了。这会导致我们昼夜规律的混乱，而且有研究表明生物钟与外界自然的昼夜循环不一致时，糖尿病、癌症、心脏病、甚至抑郁的发病率都会上升。

IT DEPENDS ON THE KIND OF DEVICE and how long people are being exposed to it, but there’s clearly a potential for suppressing melatonin in the evening, which is the hormone we start producing a couple of hours prior to bedtime. Melatonin is essentially a nighttime or darkness signal, telling us it’s time to go to bed. So, if you delay the onset of that signal in the evening, by being exposed to too much light coming from those devices, you may be delaying sleep times. Then, if you have a fixed wake up time and can’t sleep in to compensate, you are experiencing sleep deprivation. Even if you filter the light of the display or somehow protect yourself from it, it may be just as bad, because you’re still depriving yourself of sleep by staying awake to use the device.

这取决于电子设备的种类和人们使用的时长。但使用电子设备就极有可能抑制夜间褪黑激素的分泌，褪黑激素是睡前几小时开始分泌的一种激素，其实是夜间或黑暗的信号，告诉我们到睡觉时间了。所以，如果推迟夜间这一信号的发出，暴露在这些设备所发出的过多光亮之下，可能就是在推迟睡眠时间，而且如果早上起床时间固定还不能补觉的话，你可能会缺觉。即使你将屏幕调暗，或者以某种方式保护自己不受光的影响，结果也一样，因为熬夜使用电子设备仍然会缺觉。

Sleep deprivation has been linked to a series of things—it’s been shown that after five consecutive days of five hours of sleep instead of eight hours, people can become pre-diabetic or become hungrier. In the short-term, you become sleepier during the day, and you may reduce daytime performance. And then long-term, you may have more serious consequences, such as increased risk for obesity, diabetes, cardiovascular disease, and even increased risks of cancer. I’m not saying that these self-luminous displays cause cancer. But you want to minimize disruption of circadian rhythms and the curtailment of sleep as much as possible.

睡眠不足会有一系列后果——有研究表明连续五天只睡五小时而睡不够八小时的话，人会进入糖尿病前期，或更容易饿。短期内白天会更困，而且表现欠佳。长期睡眠不足会有更严重的后果，比如患肥胖、糖尿病和心血管疾病的风险都会增加，甚至患癌症的风险也会增加。我不是说这些发光的屏幕会致癌，但你也是想尽量减少对身体昼夜规律的破坏，保证充足睡眠。