When light enters the eye it next hits the lens, which is located behind the iris and it is transparent. Like all lenses, they are usually used to focus light, and this is what the lens of the eye does. It focuses light rays on the back of the eyeball to the retina. This part is home to millions of cells that are sensitive to light. The retina takes the light and changes it to signals which are sent to the brain. The brain in turn is able to tell a person what they are seeing. The image received in the eye is actually upside down when the optic nerve, like a high speed telephone line, sends the signal to the brain, When the brain receives it, though, the image seen is flipped right-side up. This happens so fast; a person won't even realize what is happening between the eyes and brain.
光进入眼睛后照在虹膜后面的透明的晶状体上。如同所有的透镜,晶状体也用于将光聚焦。它将光线聚焦到眼球后部的视网膜上。这部分由数百万光敏细胞组成。视网膜接收光线,并将其转换成发送到大脑的视觉信号。而大脑则告诉人眼所看到的画面。眼睛接收到的图像实际上是颠倒的,视神经像高速电话线将信号发送到大脑,当大脑接收到它所看到的图像被向右朝上翻。这个过程发生的太快以致人无法意识到眼睛到大脑之间发生的这一系列活动。
There is also a muscle located in the eye called the ciliary muscle. This muscle changes the shape of the lens when things are needed to be seen up close, far away, or out of the corners of the eyes. The lens becomes thicker when a person needs to see something up close, like reading, but becomes thinner when seeing something far away, like when riding a bike. The largest eye part is the vitreous body, which takes up about 2/3 of the volume of the eye, as well as giving the eye its shape.
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2020-09-15
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