Things work fine

How does ... the eye work?

How do you see

Before you can see something, a lot of small work steps have to be carried out in the eye - and at an incredibly high speed. In order for us humans to be able to see an object, light has to fall on it, for example from the sun or a lamp. The object then automatically reflects the light. That means he throws it back. By looking at the object, we take in this reflected light through the eyes.

The light first penetrates the conjunctiva and the cornea up to the pupil. The pupil is the black "hole" in the middle of the eye. It controls how much light comes into the eye. When it's dark, the pupil dilates so that enough light can be absorbed. When it's very bright, make it as small as possible so that too much light doesn't get through. The colored circle around the pupil is called the iris. So when you talk about the color of the eyes, you mean the color of the iris. It is a muscle ring that aids the pupil in shrinking and enlarging.

Chopsticks and cones

Once it has crossed the pupil, the light hits the lens. Here it is bundled and broken - that is, what is seen is turned upside down. So it depends on the retina. All possible information about what has been seen is now collected there. There are millions of tiny helpers for this: the chopsticks and the cones. The chopsticks are responsible for recognizing how light or dark what is seen is. The cones are responsible for ensuring that you can see it sharply and, above all, in color. However, the cones only work when there is enough light. This is the reason why you can only see everything blurred and gray in the dark: You then only see with the chopsticks!

The information collected is passed on to the optic nerve. This brings them directly to the brain. Only then are they evaluated and put together to form a correct image - the image that you then see the right way round.

Did you know that the eye is really well protected?

Because the eyes are so important, but also sensitive, the body protects them particularly well. The eyelids protect them from too much brightness and from things that could get into the eye. The tear fluid is there to keep the eyes always moist and to wash dirt out of the eye. The eyelashes and eyebrows are also there to protect the eyes: They prevent dirt and sweat from getting into the eyes.

Vision problems

In order to see things at different distances, the eye has to adjust each time. As you get older, however, the eye can usually no longer focus as sharply as before. That's why many wear glasses in old age. But there are other problems with vision:

  • Myopia: If you are nearsighted, you can see close things well, but far away things are very blurred. This is because the parts of the eye don't work perfectly with each other. The light beams are bundled by the lens in such a way that they meet in front of the retina. Myopia is often congenital. But it also matters how you behave and how you look after your eyes. Reading in poor light, for example, can promote myopia. You can find out more here: Playing outside: For really good eyes

  • Farsightedness: If you are farsighted, you can only see things near by blurred. Here the light rays are bundled in such a way that they would only really meet behind the retina. As with nearsightedness, the eye can easily be helped with glasses.

  • Color blindness: Some people are color blind. For example, you can't tell green from red. The reason for this lies in the cones. They are either disturbed or absent. Color blindness is most common in men and boys.