28 Incredible Eyes-Low

Incredible Eyes FOCUS Question How do eyes help animals survive?

眼睛是如何帮助动物生存的?

Why Eyes? If you look at your eyes in the mirror, you will see the pupil and the iris. The pupil is the dark hole in the center. The iris is the colored part. These two parts work together to let light into the eye. Have you tried to take a photo in a dark room? The picture will look better if you use a flash. Light from the flash reflects off the items in the room. Reflected light enters the camera and the camera records the image. Animal eyes do something similar. They take in reflected light and the brain makes sense of the image.

为什么眼睛?如果你在镜子里看你的眼睛，你会看到瞳孔和虹膜。 瞳孔是中心的黑洞。 虹膜是有颜色的部分。 这两个部分一起工作，让光线进入眼睛。 你试过在黑暗的房间里拍照吗? 如果你用闪光灯，照片会更好看。 闪光灯发出的光反射在房间里的物品上。 反射光进入照相机，照相机记录下图像。 动物的眼睛也有类似的功能。 它们吸收反射光，大脑就能理解图像。

How the Eye Works When reflected light enters the eye, it passes through the cornea, a thin, clear covering. Next, the light goes into the pupil. Eye muscles on the iris control the pupil by making it larger or smaller. This lets in more or less light. The lens is the curved structure in your eye. that bends light to focus an image onto the back of the eye. In the back of the eye is the retina. The image that forms there is actually upside down! The brain fixes this and flips the image to make it right-side-up.

当反射光进入眼睛时，它会穿过角膜，角膜是一层薄而透明的覆盖物。 接下来，光线进入瞳孔。 虹膜上的眼部肌肉通过使瞳孔变大或变小来控制瞳孔。 这会让或多或少的光线进来。 晶状体是你眼睛里的弯曲结构。 它可以弯曲光线，将图像聚焦到眼睛后部。 在眼睛的后面是视网膜。 在那里形成的图像实际上是颠倒的!大脑会修复这个问题，并将图像翻转到正上方。

Roses Are Red What makes a green leaf look green? The answer begins with understanding sunlight. You can make a rainbow with a prism, which separates the Sun's white light into the many colors we see. When sunlight hits a leaf, some light is absorbed and some is reflected. A green leaf absorbs all the colors of light except green. The reflected green light is the color you see. Your eye has small cells in the retina called cones that respond to different colors of light. When you see green, the cones that react to the color green send signals to your brain. Your brain processes that information and tells you that you are seeing green. Do You Know? Some animals such as snakes, vampire bats and bedbugs can "see" heat. One form of heat is infrared light. which is outside the spectrum of light that humans can see.

是什么让绿叶看起来是绿色的? 答案从了解阳光开始。 你可以用棱镜做出彩虹，棱镜把太阳的白光分离成我们看到的许多颜色。 当阳光照射到树叶上时，一些光被吸收，一些被反射。 绿叶吸收除了绿色以外的所有颜色的光。 反射的绿光就是你看到的颜色。 你眼睛的视网膜上有一种叫做视锥细胞的小细胞，它们对不同颜色的光做出反应。 当你看到绿色时，对绿色做出反应的视锥细胞会向你的大脑发送信号。 你的大脑处理这些信息，然后告诉你你看到的是绿色。 你知道吗?蛇、吸血蝙蝠和臭虫等动物能“看到”热量。 热的一种形式是红外光。 这在人类能看到的光谱之外。

Seeing in the Dark Unlike people, cats are most active at night. How do they see in the dark? Cats have a shiny, reflective surface inside their eyes. This surface reflects light onto the retina to help cats see in the dark. At night, their pupils open up to let in more light. Other nocturnal animals, like deer, have similar eyes. Deep-sea animals like the giant squid and the octopus live in darkness. They have some of the largest eyes of all animals. Large eyes can let more light in to help these animals see in the dark.

与人类不同，猫在晚上最活跃。 他们在黑暗中怎么看东西? 猫的眼睛内部有一个有光泽的反射表面。 这个表面将光线反射到视网膜上，帮助猫在黑暗中看到东西。 晚上，它们的瞳孔会打开，让更多的光线进入。 其他夜行动物，如鹿，也有类似的眼睛。 深海动物如巨型乌贼和章鱼生活在黑暗中。 它们的眼睛是所有动物中最大的。 大眼睛可以让更多的光线进入，帮助这些动物在黑暗中看到东西。

Eat or Be Eaten One of the biggest reasons animals need vision is to be able to hunt for food and to avoid being hunted. Animals that hunt are called predators and the animals they eat are called prey. Most predators, including owls, have eyes on the front of their heads. This lets them focus both eyes forward, giving them stereoscopic (STEH-ree-oh-SKOP-ick) vision. Their two eyes create a single image. This ability helps animals tell how far away an object is. Try covering one eye. It's hard to figure out how near or far something is without stereoscopic vision. The owl's prey, a squirrel, has eyes on the sides of its head. This allows the squirrel to spot predators on all sides without moving around and risking getting noticed.

动物需要视觉的最大原因之一是能够寻找食物并避免被猎杀。 捕食的动物叫捕食者，它们吃的动物叫猎物。 大多数食肉动物，包括猫头鹰，眼睛都长在头的前面。 这让他们的双眼向前聚焦，从而获得立体视觉。 它们的两只眼睛形成了一个单一的图像。 这种能力帮助动物分辨物体有多远。 试着遮住一只眼睛。如果没有立体视觉，很难判断某物有多近或多远。 猫头鹰的猎物是一只松鼠，它的眼睛长在头部两侧。 这使得松鼠可以发现四面八方的捕食者，而不用四处走动，也不会有被发现的风险。