文章大意:本文是一篇说明文。文章针对防蓝光眼镜进行了科普,蓝光实际上有其好的一面,有助于人们在白天维持良好的情绪、警觉性和睡眠—清醒周期,但在夜间蓝光会抑制褪黑激素的释放,影响人们的睡眠,而科学研究证实戴防蓝光眼镜可以帮助入睡,但是对缓解眼疲劳、预防眼部疾病并没有效果。
The sales advertisements tempt (诱惑): Blue-light-blocking glasses are supposed to protect eyes from the effects of short-wave length light emitting from our smartphones, computer screens and LED lights. Given how much time we spend on our devices, this sounds like a smart investment, right? After all, eye strain (疲劳) is a real issue and can lead to poor sleep and even eye diseases. The glasses can cost $15 all the way up to several hundred dollars. But do they work?
Elizabeth Esparaz, an ophthalmologist (眼科专家) based in Cleveland, Ohio, says the science that manufacturers share as they promote these glasses can be confusing. For starters, blue light is not just about tech devices, and it’s not always bad. “The sun emits a much higher intensity of blue light than human-made devices, which helps our mood, alertness and sleep-wake cycle,” says Dr. Esparaz.
The problem is blue light at night: It contains the release of melatonin. “Melatonin helps regulate our circadian rhythms (生理节奏) and makes us sleepy,” says Dr. Esparaz.
So, in theory, wearing blue-light-blocking glasses should help people who watch movies in bed or read from a tablet at night avoid sleeplessness. A review study from the University of Oklahoma that looked al 24 previous studies found that people affected by sleep disorders, jet lag and shift work fell asleep faster after using these glasses.
As for eye strain, a 2021 Australian study showed that those wearing the glasses did not experience less eye strain than those using clear glasses. And a 2018 review study, also by Australian researchers found insufficient evidence that they prevent certain eye diseases.
“These glasses aren’t going to be harmful,” says Dr. Esparaz, But, she adds, a lack of standardization in the industry means there’s no way to know if one pair is better than another. A more reliable solution: Turn on the blue-light-filtering function on your devices and limit screen time before bed. To help with eye strain, Dr. Esparaz suggests taking breaks and using lubricating eye drops.
32. What is Dr. Esparaz’s attitude toward business publicity?
A.Unclear. | B.Tolerant. | C.Approving. | D.Doubtful. |
33. What can we learn about blue light from the first two paragraphs?
A.It can be beneficial. | B.It may improve sleep. |
C.It actually causes health issues. | D.It merely comes from digital devices. |
34. Australian studies found that wearing blue-light-blocking glasses ________.
A.helps prevent eye disease | B.are not harmful to eyesight |
C.contributes to no less eye strain | D.benefits those with sleep disorders |
35. What might be the best title of this passage?
A.Blue-light-blocking Glasses: Your Best Choice | B.Blue-light-blocking Glasses: Good or Bad |
C.Blue-light-blocking Glasses: A Good Business | D.Blue-light-blocking Glasses: Smart and Cool |