A
(2020·济南模拟)We humans love to stare into our smart devices. We gaze for hours—about 10 hours and 39 minutes a day—at our computers, smartphones, tablets and televisions. Is all this staring bad for us? It might be, mainly because as we stare at our devices we are exposing ourselves to blue light.
Blue light is a type of electromagnetic(电磁的) radiation with a very short wavelength that produces a high amount of energy. While it’s true that light can damage our eyes under certain circumstances, there’s no scientific evidence suggesting that blue light is harmful to our eyes. But many people still think it is, which is why bluelightblocking glasses are so popular. So do the glasses work?
“Everyone is very concerned that blue light may be causing damage to the eye, but there’s no evidence that it may be causing serious damage，” Dr. Rahul Khurana, clinical spokesman for the American Academy of Ophthalmology, told Business Insider.
Blue light exposure is nothing new. In fact, the sun is the largest source of blue light. Moreover, blue light is also present in LED light. But if blue light isn’t harmful, then why are we constantly rubbing our eyes when we’re looking at our screens? The answer is eyestrain (眼疲劳): More than 60 percent of people experience eye problems associated with digital eyestrain. And blue light, it seems, isn’t the cause. Instead, our eyes are so strained because most of us blink less when we stare at our digital devices. So if eyestrain is the issue, bluelightblocking glasses are probably of little use.
【解题导语】 该文主要探讨了蓝光是否对我们的眼睛有害的问题。
1．What do we know about blue light?
A．It is a kind of nuclear radiation.
B．It has the shortest wavelength.
C．It may come from electronic devices.
D．It consumes a great deal of energy.
C 解析：推理判断题。根据第一段最后一句“It might be, mainly because as we stare at our devices we are exposing ourselves to blue light.”可推知，电子设备会发出蓝光。
2．What causes the popularity of bluelightblocking glasses?
A．Evidence of their benefits to eyes.
B．Belief in blue light’s harmful effect.
C．Widespread use of smart devices.
D．Scientific understanding of blue light.
B 解析：细节理解题。根据第二段中的“there’s no scientific evidence suggesting that blue light is harmful to our eyes. But many people still think it is, which is why bluelightblocking glasses are so popular.”可知，防蓝光眼镜流行的原因是人们认为蓝光会对眼睛有害。
3．What can be inferred from Paragraph 4?
A．Blue light exposure is hardly avoidable.
B．Eye problems are not easy to deal with.
C．Blue light may connect with tired eyes.
D．Rubbing eyes makes people strained.
A 解析：推理判断题。根据第四段的前三句“Blue light exposure is nothing new. In fact, the sun is the largest source of blue light. Moreover, blue light is also present in LED light.”可知，阳光是蓝光最大的来源，而且蓝光也存在于LED灯中。由此可推知，接触蓝光几乎是不可避免的。
4．According to the text, wearing bluelightblocking glasses may be ________．
A．tiring B．harmful
C．useless D．beneficial
C 解析：细节理解题。根据最后一段最后一句“So if eyestrain is the issue, bluelightblocking glasses are probably of little use.”可知，戴防蓝光眼镜可能是没有用处的。
