【英语时差8,16】黄色太阳镜

Look at a cloud-filled sky, then look again through a pair of amber¹ sunglasses.

You'll be surprised to see the hazy², bluish clouds jump suddenly into focus, revealing a world of unexpected detail. Many skiers use amber sunglasses too, to help see detail in white banks of snow. On today's Moment of Science, we'll learn how amber-tinted sunglasses make things appear so much sharper.

The answer has as more to do with your eyes than it does with the sunglasses. Behind the pupil of your eye is a natural lens like a tiny bag of transparent³ jello⁴. This lens focuses images on the back of your eyeball the same way a camera's lens focuses images onto film.

Unfortunately, even healthy eyes can't focus everything perfectly⁵. This is because each color of light focuses slightly differently through a lens. Imagine a slide projector⁶ showing a red and a blue image on the same screen. If you focus the red image sharply, the blue one will be slightly blurry⁷. If you twist the knob to focus the blue image, the red one will drift slightly out of focus. You can only get ultra-sharp focus of one color at a time.

Healthy eyes are set to focus yellow, the middle of the color spectrum⁸. This is great for yellow--and pretty good for green and orange--but it makes red and blue appear slightly out of focus. White sunlight contains all the colors, so the red and blue extremes will make any white object seem somewhat hazy. Amber sunglasses block the blue and red parts of sunlight, letting you concentrate on the yellow colors that are easier to focus. Without blue and red, everything seems sharper.   

1 amber   

n.琥珀；琥珀色；adj.琥珀制的

参考例句：

• Would you like an amber necklace for your birthday?你过生日想要一条琥珀项链吗？
• This is a piece of little amber stones.这是一块小小的琥珀化石。

2 hazy   

adj.有薄雾的，朦胧的；不肯定的，模糊的

参考例句：

• We couldn't see far because it was so hazy.雾气蒙蒙妨碍了我们的视线。
• I have a hazy memory of those early years.对那些早先的岁月我有着朦胧的记忆。

3 transparent   

adj.明显的，无疑的；透明的

参考例句：

• The water is so transparent that we can see the fishes swimming.水清澈透明，可以看到鱼儿游来游去。
• The window glass is transparent.窗玻璃是透明的。

4 jello   

n.凝胶物，果冻

参考例句：

• We have ice cream,pie,cake or jello.我们要冰淇淋、馅饼、蛋糕或是果冻。
• She likes jello very much.她很喜欢吃果冻。

5 perfectly   

adv.完美地，无可非议地，彻底地

参考例句：

• The witnesses were each perfectly certain of what they said.证人们个个对自己所说的话十分肯定。
• Everything that we're doing is all perfectly above board.我们做的每件事情都是光明正大的。

6 projector   

n.投影机，放映机，幻灯机

参考例句：

• There is a new projector in my office.我的办公室里有一架新的幻灯机。
• How long will it take to set up the projector?把这个放映机安放好需要多长时间？

7 blurry   

adj.模糊的；污脏的，污斑的

参考例句：

• My blurry vision makes it hard to drive. 我的视力有点模糊，使得开起车来相当吃力。 来自《简明英汉词典》
• The lines are pretty blurry at this point. 界线在这个时候是很模糊的。 来自《简明英汉词典》

8 spectrum   

n.谱，光谱，频谱；范围，幅度，系列

参考例句：

• This is a kind of atomic spectrum.这是一种原子光谱。
• We have known much of the constitution of the solar spectrum.关于太阳光谱的构成，我们已了解不少。