介绍： 20180401晨读原文本
Six ways to avoid eyestrain
眼睛累了怎么办？七种办法帮你消除眼疲劳（下）

Exercise your eyes
锻炼眼睛
Staring at a screen continuously for hours on end causes focusing fatigue. To avoid this, many eye experts recommend the “20-20-20 rule” – looking away from your phone/computer screen ev...

介绍： 20180401晨读原文本
Six ways to avoid eyestrain
眼睛累了怎么办？七种办法帮你消除眼疲劳（下）

Exercise your eyes
锻炼眼睛
Staring at a screen continuously for hours on end causes focusing fatigue. To avoid this, many eye experts recommend the “20-20-20 rule” – looking away from your phone/computer screen every 20 minutes and focusing on an object at least 20ft away for at least 20 seconds. The science behind this trick is that looking at objects at a distance relaxes the focusing muscle in the eye, helping to reduce fatigue.
连续数小时盯着屏幕会导致聚焦性眼疲劳。为了避免这一点，很多眼科专家推荐“20-20-20规则”，也就是每20分钟让眼睛离开手机或电脑屏幕，盯着20英尺（约合6.1米）外的物体看至少20秒。这种做法的科学道理是看远处的物体能放松眼部的紧张肌肉，帮助缓解眼疲劳。

Blink
眨眼
We don’t realize it, but our eyes blink differently and less frequently when we are staring at our phone or computer screen. Normally, we blink about 15 times a minute, but this drops by a third while we are looking at screens – and the blinks that do occur are typically partial blinks, meaning that during the blink phase the upper lid doesn’t come all the way down. This reduced blinking ability makes it difficult for the eyeball to remain moist, since the tears coating the eye evaporate more rapidly. If you find you have dry eyes as a result of excessive screen use, experts recommend either using artificial tears to refresh your eyes or resetting your natural blink frequency through an exercise where you blink slowly 10 times, as if shutting your eyes for sleep, every 20 minutes.
我们的眼睛在盯着手机或电脑屏幕时眨眼方式不同，频率也更低，这一点我们并没有注意到。我们一般每分钟眨眼15次，但盯着屏幕时一分钟只眨眼10次，而且属于典型的不完全眨眼，也就是眨眼时上眼皮并没有完全落下。这种不完全眨眼使眼球很难保持湿润，因为眼球表面的泪水蒸发更快。如果你发现因为过度使用屏幕而眼睛发干，专家建议你使用人工泪液消除眼疲劳，或者进行眼部锻炼，也就是缓慢眨眼10次来重置自然的眨眼频率，就好比每20分钟让你的眼睛睡个觉。

词汇学习
1. frequency ['friːkwənsi] n. 频率
2. evaporate [ɪ'væpəreɪt] v. (使)〔液体〕汽化，(使)蒸发
3. excessive [ɪk'sesɪv] adj. 过多的；过分的
4. artificial [ɑːtɪ'fɪʃ(ə)l] adj. 人造的；虚伪的
5. refresh [rɪ'freʃ] v. 更新；使……恢复
6. typical ['tɪpɪkəl] adj. 典型的，有代表性的
7. remain [rɪ'meɪn] v. 保持；留下 n. 遗迹；剩余物