What is light?

The light we perceive is electromagnetic radiation of a wavelength in the range of 380 – 780 nanometers (nm). The different wavelengths of light in this spectrum determine the color. For example, the color red is in a wavelength range of 650 – 750 nm, green in the range of 490 – 575 nm and blue at 420 – 490 nm.

Even more precisely, light can be divided into the smallest particles, so-called photons. These are the smallest units of light that can cause a stimulus to the eye. In order for the stimulus to be noticeable, an incredible number of these photons must of course trigger a stimulus to the eye.

What is a neuron?

A neuron generally refers to a nerve cell. Nerve cells can take over very different functions. However, they are mainly receptive to information in the form of electrical impulses, can change these impulses depending on the type of nerve cell and then transmit them via cell extensions (axons, synapses) to one or, much more frequently, several other nerve cells.

Nerve ending (dendrite)
Messenger substances, e.g. dopamine
Other nerve ending (axon)

What is the visual pathway

The visual pathway is the connection between the eye and the brain through numerous nerve processes. Starting at the eye, it begins with the retina and continues in the optic nerve to the brain. In the Corpus geniculatum laterale, near the thalamus (both important brain structures), a switch to visual radiation then takes place. This radiation then radiates into the posterior lobe (occipital lobe) of the brain, where the visual centers are located.

What are the optical visual centers?

Optical visual centers are areas in the brain that mainly process information coming from the eye and initiate appropriate reactions. This includes mainly the visual cortex, which is located in the rear part of the brain. It can be divided into a primary and secondary visual cortex.

Here, what is seen is first consciously perceived, then interpreted and classified. There are also smaller visual centers in the brain stem, which are responsible for eye movements and eye reflexes. Not only are they important for healthy vision, they also play an important role in examinations to determine, for example, which part of the brain or visual pathway is damaged.