Can you guess what the fastest moving muscles in the human body are?

您能猜出人體中運動最快的肌肉是什麼嗎？

Here's a hint, they move in the blink of an eye.

給你個提示，它們一眨眼就會移動。

Now what do you think?

現在你怎麼想？

Yup, you guessed it, the six muscles that help you blink your eyes are the fastest moving muscles in your body.

是的，你猜對了，幫助你眨眼的六塊肌肉是你身體中運動最快的肌肉。

Let's go on a sightseeing field trip and explore the inner workings of the human eye.

讓我們進行一次實地考察，探索人類眼睛的內部構造。

The human eye is located inside a hollow area of the skull called the eye socket.

人類的眼睛位於頭骨的一箇中空部位，稱為眼窩。

The eyelid is what protects the front part of the eye.

眼瞼保護著眼睛的前部。

It does so by blinking.

它通過閃爍來實現。

Blinking is what helps keep your eyes clean by keeping dirt and substances out of the eye.

眨眼可以防止灰塵和物質進入眼睛，從而保持眼睛清潔。

Blinking also prevents the eyes from getting too dry.

眨眼還能防止眼睛過於乾燥。

Lacrimal glands are responsible for making tears, which also help keep your eyes clean.

淚腺負責製造淚液，也有助於保持眼睛清潔。

Here is an interesting fact about blinking.

這裡有一個關於眨眼的有趣事實。

It can be both voluntary, meaning you choose to do it, and involuntary, which means it happens automatically as a reflex.

它既可以是自願的，即你選擇去做，也可以是非自願的，即作為一種條件反射自動發生。

This reflex happens when the light is too bright or if you need to shut your eyes quickly for protection.

當光線太亮或需要快速閉眼保護時，就會出現這種反射。

Have you ever looked in the mirror and wondered what the white part of your eye is called?

您是否曾經照過鏡子，並想知道您眼睛的白色部分叫什麼？

It is called the sclera.

它被稱為鞏膜。

The sclera is the outer covering of your eyeball and is made of super strong material.

鞏膜是眼球的外層覆蓋物，由超強材料製成。

It also has blood vessels, which helps a blood flow to your eyeball.

它還有血管，有助於血液流向眼球。

Next up, the cornea.

接下來是角膜。

The cornea is a transparent dome that is located in the front of the colorful part of your eye.

角膜是位於眼睛彩色部分前方的一個透明圓頂。

It helps the eye focus when it's exposed to light.

當眼睛受到光線照射時，它能幫助眼睛聚焦。

Think of it this way.

這樣想吧。

The cornea is kind of like a window that your eye sees through.

角膜就像是眼睛看東西的窗戶。

Pretty cool, right?

很酷吧？

Another important part of the human eye is the anterior chamber.

人眼的另一個重要部分是前房。

It is the space between the cornea and the iris and is filled with a transparent fluid that helps keep the eye healthy.

它是角膜和虹膜之間的空隙，裡面充滿了有助於保持眼睛健康的透明液體。

What color are your eyes?

你的眼睛是什麼顏色的？

Did you know that the colorful part of your eye is called the iris?

您知道眼睛的彩色部分叫做虹膜嗎？

And what about the black circle in the middle?

中間的黑圈又是怎麼回事？

That's right.

這就對了。

It is the pupil.

是學生。

The iris and the pupil work together in an interesting way.

虹膜和瞳孔以一種有趣的方式相互配合。

Light travels through the iris before arriving at the pupil.

光線穿過虹膜，然後到達瞳孔。

Here is an interesting fact.

這裡有一個有趣的事實。

There are muscles that are attached to the iris that actually change its shape.

虹膜上附著的肌肉實際上可以改變虹膜的形狀。

This is important because this process is what controls the amount of light that goes through the pupil.

這一點很重要，因為這一過程控制著通過瞳孔的光量。

The pupil is what lets light enter your eye.

瞳孔是光線進入眼睛的通道。

It adjusts to the amount of light by opening wider when you need more light and shrinks when there is plenty of light available.

它能根據光量進行調節，在需要更多光線時打開更大，在光線充足時縮小。

And here we thought eyes were just nice to look at.

我們還以為眼睛只是好看而已。

So what happens after light enters your eye through the pupil?

那麼，光線通過瞳孔進入眼睛後會發生什麼呢？

It hits the transparent lens located just behind the iris.

它擊中位於虹膜後方的透明透鏡。

Like all lenses, it is usually used to focus light and it focuses light rays all the way to the back of the eyeball to a part called the retina.

與所有透鏡一樣，它通常用於聚焦光線，並將光線一直聚焦到眼球后部，到達一個叫做視網膜的部位。

The retina is home to millions of cells that are light-sensitive.

視網膜上有數百萬個感光細胞。

These cells are called rods and cones.

這些細胞被稱為視杆細胞和視錐細胞。

Rods see in black, white, and gray, as well as can detect the differences in colors, and they pass along the shapes of what you see.

視杆能看到黑、白、灰三色，也能檢測到顏色的差異，並能傳遞所看到的形狀。

On the other hand, there are three different kinds of cones, and these cones are most helpful when you experience brighter light.

另一方面，有三種不同的錐狀體，這些錐狀體在遇到較亮的光線時最有幫助。

Cones also help you to see all different kinds of colors and their shades.

錐形筒還能幫助您看到各種不同的顏色及其深淺程度。

In short, the retina takes all of the gathered light in your eye and uses rods and cones to change it to signals that are sent to the brain.

簡而言之，視網膜接收眼睛中所有聚集的光線，並利用視杆細胞和視錐細胞將其轉變為信號，然後發送到大腦。

This is done via the optic nerve.

這是通過視神經實現的。

The optic nerve carries all of this information to the brain, and that is how the brain is able to tell you what you are seeing.

視神經將所有這些資訊傳遞給大腦，這樣大腦就能告訴你看到了什麼。

Here is an interesting fact.

這裡有一個有趣的事實。

By the time an image reaches the retina, it is actually upside down.

當影像到達視網膜時，它實際上是顛倒的。

This is because the image is refracted, or bent, as it moves through the different parts of the eye.

這是因為影像在通過眼睛的不同部位時會發生折射或彎曲。

But when the optic nerve carries this information to the brain, the image is flipped right side up.

但當視神經將這些資訊傳遞給大腦時，影像就會被翻轉過來。

This happens so fast that you cannot even tell it is happening.

這一切發生得太快，以至於你根本無法察覺。

There are also a couple more parts of the eye that are important.

眼睛還有幾個重要的部分。

First, the ciliary muscle, which changes the shape of the lens of your eye when you need to see things close up, far away, or out of the corners of your eyes.

首先是睫狀肌，當您需要看近處、遠處或眼角的東西時，它能改變眼球晶狀體的形狀。

Last is the vitreous body, which is the largest part of the eye.

最後是玻璃體，它是眼睛最大的部分。

It takes up about two-thirds of the volume of the eye, and gives the eye its shape.

它約佔眼球體積的三分之二，並賦予眼球形狀。

We knew that the eyeballs were cool, but who knew that they were this complex?

我們知道眼球很酷，但誰知道它們如此複雜？

We have learned a ton of new information about the human eye.

我們學到了大量關於人類眼睛的新資訊。

Let's see what you remember.

讓我們看看你還記得什麼。

Fill in the blank.

填空。

The part of the eye that sends signals to the brain is called the blank nerve.

眼睛向大腦發送信號的部分稱為空白神經。

Optic nerve.

視神經

True or false.

真或假。

The retina has two types of cells, called rods and cones.

視網膜有兩種細胞，分別稱為視杆細胞和視錐細胞。

True.

沒錯。

Which part of the eye is the colorful part?

眼睛的哪個部分是多彩的？

The iris.

虹膜

Great work, visionaries!

幹得好，有遠見的人！

The eyes are an extremely important part of your body, and should always be taken care of.

眼睛是人體極其重要的組成部分，應該時刻得到呵護。

The next time you are outside, put a pair of shades to protect those pretty peepers from the sun's rays.

下次外出時，戴上一副墨鏡，保護漂亮的眼睛不受陽光照射。

And think about all of the different parts of your eye working together to help you see everything around you.

想一想眼睛的各個部分是如何相互配合，幫助你看清周圍的一切的。

Hope you had fun learning with us!

希望你能和我們一起愉快地學習！

Visit us at learnbright.org for thousands of free resources and turnkey solutions for teachers and homeschoolers.

訪問我們的網站 learnbright.org，為教師和家庭教育者提供成千上萬的免費資源和全套解決方案。