How is an eyeball made?

How does the eye work?

Behind it is the transparent glass body. It consists of a jelly-like mass that gives the eyeball its plump, elastic shape. The vitreous is like this and that transparent. This is an important prerequisite for good vision. In old age, however, clouding can occur: If, for example, it is no longer “crystal clear”, one speaks of a cataract. This can also become cloudy in old age. Scarring can also be the cause.

In many people, cloudy substances develop in the vitreous, which are harmless and do not interfere with the visual function. But sometimes you get the impression that small threads or insects are buzzing around in front of your field of vision. This phenomenon is therefore called Mouches volantes (French for "flying mosquitoes"). Serious opacities of the vitreous humor that hinder vision and should be treated are less common and are usually related to one of the eye. The vitreous humor can also become cloudy if it bleeds into the eyeball. The inside of the back wall of the eyeball is lined by the (). In its back area - the so-called fundus - it contains millions of. The refraction of the lens creates a sharp image of the things that are currently being viewed. They receive these light stimuli and convert them into nerve signals.

There are two types of in the: cones and chopsticks.

  • Cones are responsible for seeing colors.
  • Chopsticks enable “black and white vision”. They require less light and enable vision during twilight and at night.

These two types of sensory cells are not evenly distributed over the. Most of the cones are located roughly in the middle of the fundus, the "yellow spot" (). This is the area where we can see the most clearly.

The nerve signals from the cones and rods are passed on to the brain via the optic nerve. There they are processed - among other things with the information from the other eye - and put together into a consciously perceived image.