Question

    Blue light before bedtime can make it harder to sleep, and the screens on phones, computers, and televisions send out plenty of blue light. This is all true. But if you're focused on blue light as a major problem affecting your sleep or your eye health, it's time to look at it from another aspect.

As Philip Yuhas, a professor of vision, writes at The Conversation, blue light isn’t a uniquely technological evil. It's part of sunlight, and your eyes are exposed to plenty of it all the time. You ' re fine. There are studies in mice that have found blue light can damage their eyes, but mice are nocturnal creatures (夜行动物) whose eyes are different from ours. The pigments (色素) and the lenses (晶状体) of our eyes actually block blue light fairly well--so in a sense, we already have built-in blue blocking protection

Adding more protection isn't likely to help though. You can buy glasses and screen filters (滤光片) that block blue light, but Yuhas points out they are probably a waste of money: these products do not block out much blue light. The leading blue-blocking anti-reflective coating, for example, blocks only about 15% of the blue light that screens send out. You could get the same reduction just by holding your phone another inch from your face.

The American Academy of Ophthalmology doesn't recommend blue-blocking products, either. Instead if you're concerned about your eye health or your ability to get to sleep on time, you already know what to do:

Put the screens away at bedtime. Read a book or find something else to do. While you're using screens take a 20-second break every 20 minutes to look at something 20 feet away ( the "20-20-20 " rule ). If you get dry eyes when you look at screens for a long time, use eyedrops labeled artificial tears.

1.What do people think of blue light generally?

A.It is a necessary part of sunlight. B.It is magical and rare.

C.It is the major factor affecting sleep. D.All electronics send out blue light.

2.What did the studies in mice find?

A.Mice can see clearly in the dark. B.Our eyes actually block blue light well.

C.Eyes can be long exposed to blue light. D.Blue light can damage mice's eyesight.

3.What can we know about blue-blocking products?

A.They block only 15% of the blue light. B.Few have much effect on the blue light.

C.They can prevent much harmful lights. D.They are thought highly of by experts.

4.What could be the best title for the text?

A.How can Blue Light Be Prevented? B.Why does Blue Light Make Sleeping Hard?

C.Are Blue-blocking Products Necessary? D.What will Blue Light Affect Actually?

Answer

1.C

2.D

3.B

4.C

【解析】

本文是一篇说明文。主要讲述蓝光其实对我们的眼睛没有太大的伤害，防蓝光产品对蓝光几乎没有什么作用，不建议使用，如果害怕蓝光影响睡眠，建议不要长时间盯着屏幕看，多休息。

1.细节理解题。根据文章第一段Blue light before bedtime can make it harder to sleep, and the screens on phones, computers, and televisions send out plenty of blue light. This is all true. But if you're focused on blue light as a major problem affecting your sleep or your eye health, it's time to look at it from another aspect. 睡觉前的蓝光会让人更难入睡，而手机、电脑和电视的屏幕会发出大量的蓝光。这些都是事实。但是如果你把蓝光作为影响你睡眠或眼睛健康的主要问题，那么是时候从另一个角度来看待它了。由此可知，人们认为蓝光是影响睡眠的主要因素，故选C。

2.细节理解题。根据文章第二段There are studies in mice that have found blue light can damage their eyes, but mice are nocturnal creatures (夜行动物) whose eyes are different from ours. 对老鼠的研究发现蓝光会损害它们的眼睛，但老鼠是夜行动物，它们的眼睛与我们的不同。由此可知研究发现蓝光会损害老鼠的眼睛，故选D。

3.细节理解题。根据文章第三段Adding more protection isn't likely to help though. You can buy glasses and screen filters (滤光片) that block blue light, but Yuhas points out they are probably a waste of money: these products do not block out much blue light. 不过，增加更多的保护措施可能不会有什么帮助。你可以买眼镜，屏幕滤光片阻止蓝光，但Yuhas指出他们可能是浪费钱的：这些产品并不阻挡蓝光。由此可知防蓝光产品对蓝光几乎没有什么作用，故选B。

4.主旨大意题。主要讲述蓝光其实对我们的眼睛没有太大的伤害，防蓝光产品对蓝光几乎没有什么作用，不建议使用，如果害怕蓝光影响睡眠，建议不要长时间盯着屏幕看，多休息。C选项 Are Blue-blocking Products Necessary?防蓝光产品是必要的吗，符合文章中心思想，适合做标题，故选C。