時差N小時:黃色太陽鏡
觀察那布滿云彩的天空，再戴上黃色鏡片的眼鏡去觀察。
You'll be surprised to see the hazy, bluish cloudsjump suddenly into focus, revealing a world ofunexpected detail.
你會驚訝得發(fā)現(xiàn)，蔚藍(lán)朦朧的云朵突然聚焦于眼球，呈現(xiàn)出一個無比精準(zhǔn)的視界。
Many skiers use amber sunglasses too, to help seedetail in white banks of snow.
許多滑雪者也使用黃色的眼鏡，用以看清白茫茫雪地。
On today's Moment of Science, we'll learn how amber-tinted sunglasses make things appear somuch sharper.
今日時差N小時，我們將學(xué)習(xí)黃色眼鏡怎樣將視像變得更清晰。
The answer has as more to do with your eyes than it does with the sunglasses.
相比眼鏡，我們更應(yīng)該從眼睛成像原理出發(fā)找答案。
Behind the pupil of your eye is a natural lens like a tiny bag of transparent jello.
人眼瞳孔之后是透明的果凍似的自然晶狀體。
This lens focuses images on the back of your eyeball the same way a camera's lens focusesimages onto film.
就像照相機鏡頭可以把圖像聚焦在膠片上，晶狀體則把圖像聚焦到眼球的后部。
Unfortunately, even healthy eyes can't focus everything perfectly.
不幸的是，即使是正常的眼睛也不能十分完美得聚焦圖像。
This is because each color of light focuses slightly differently through a lens.
這是因為每一種不同顏色的可見光在透過晶狀體聚焦時有微小的差別。
Imagine a slide projector showing a red and a blue image on the same screen.
想象一個幻燈放映機在屏幕上同時放映紅色和藍(lán)色的圖像。
If you focus the red image sharply, the blue one will be slightly blurry.
如果你?？醇t色的圖像，藍(lán)色的圖像會顯得模糊。
If you twist the knob to focus the blue image, the red one will drift slightly out of focus.
如果你轉(zhuǎn)動旋鈕，目光集中在藍(lán)色的圖像上，紅色的圖像會輕輕漂出視線。
You can only get ultra-sharp focus of one color at a time.
人眼一次只能聚焦一種顏色。
Healthy eyes are set to focus yellow, the middle of the color spectrum.
健康的眼睛注定要聚焦位于光譜中間的黃色。
This is great for yellow--and pretty good for green and orange--but it makes red and blueappear slightly out of focus.
人眼看黃光會顯得非常清晰，看綠光和橙色光也很清楚，但是看紅光和藍(lán)光似乎顯得模糊。
White sunlight contains all the colors, so the red and blue extremes will make any white objectseem somewhat hazy.
白光包含了所有顏色的單色光，所以臨界的紅光和藍(lán)光會讓任何白色的物體看起來模糊。
Amber sunglasses block the blue and red parts of sunlight, letting you concentrate on theyellow colors that are easier to focus.
黃色鏡片則阻擋紅光和藍(lán)光，提高對比度，讓眼球聚焦在黃光上。
Without blue and red, everything seems sharper.
沒有紅藍(lán)兩色，一切似乎顯得清晰起來。
