The eyes represent the most important sensory organ of humans. They serve in particular for orientation and visual perception. However, various complaints and diseases can limit the function of the visual process.
What is the visual process?
The eyes represent the most important sensory organ in humans. In particular, they serve orientation and visual perception. The visual process takes place via complex mechanisms in the brain and eyes. The decisive factor for the transmission of images is light. This causes a reaction on the retina, which results in an electrical stimulus. With the help of certain nerves, the eyes manage to transmit the impulse to the brain. In the process, the information is already altered on its way from the retina to the brain so that other structures can process the stimuli. However, not only the mechanical process that leads to the image of the environment is part of the visual process, but also the psychological consequences that result from what is seen. After the stimuli have reached the brain, it must interpret and analyze the received impulses. The interpretation is influenced by various factors. These include, for example, experiences, memories and individual developments. As a result, perception varies from person to person and cannot be described as identical.
Function and task
In the process of vision, the incident light plays a crucial role so that the objects located in the environment can be perceived. Light is an electromagnetic radiation that occurs in waves. The different wavelengths are responsible for the differentiated colors. The smallest elements of light are formed by photons. These in turn succeed in conveying a stimulus to the eye. During the visual process, light passes through the cornea, pupil, lens and vitreous body. Only when the retina has been crossed can the image be formed. In this process, the cornea and lens refract the light at such an angle that it is possible for the eye to receive the stimuli. If the light is not refracted correctly, the result is a blurred image. This is how nearsightedness as well as farsightedness, for example, develop. The information is then received by neurons via several pathways. Particularly important here are the rod and cone cells, which have a high sensitivity to light. Neurons are the nerve cells of the human organism. Depending on their type, they can convert stimuli and transmit them in a modified form. Once the stimuli have reached the neurons, the optic nerve can transport them to the brain. Onward transmission takes place via the visual pathway. This is the connection between the eye and the brain. Its beginning can be found in the retina of the eye, and its further course is via the optic nerve. The corpus geniculatum laterale provides for a further change of the stimuli into the visual radiation. The visual radiation in turn extends into the posterior lobes of the brain. In this region, the visual centers can be localized. These manage to process the information from the retina and trigger appropriate reactions. The visual cortex, for example, is particularly important for this process. It is responsible for the conscious perception of what is seen and for the assignment of interpretations and emotions. The visual process serves humans in particular for orientation. In this way, we can assess our own situation. A total of 80 percent of all information that reaches the brain via the environment is provided by the eyes. The human eye is able to differentiate between about 150 color tones. The importance of the visual process usually only becomes clear when there are limitations to vision. The eyes do not only enable orientation, in this way it is also possible to perceive all objects. Objects can be bypassed and tools can be picked up for further processing. In addition, vision also serves the purpose of communication. This includes, on the one hand, the observation of the lips during speech, and on the other hand, facial expressions and gestures, which provide the subconscious mind with certain stimuli and information.
Diseases and complaints
The visual process can be limited in different ways. The most severe manifestation is considered to be blindness, which completely impedes visual perception.More often, however, nearsightedness or farsightedness develops. Nearsighted people perceive a blurred image of the environment. Objects that are only a few centimeters away can usually be perceived sharply. However, the greater the distance, the more the image becomes blurred. Nearsightedness is caused by a beam of light that is not optimally refracted. The light is bundled in the retina. A too long eyeball or an increased refractive power of the lens are responsible for the fact that the elements of the visual process are no longer optimally aligned. Often the triggers of nearsightedness are inherited and manifest themselves during the first three decades of life. Farsightedness, on the other hand, means that distant objects are perceived sharply, while nearby elements appear blurred. If the refractive power of the individual structures of the eye is too weak, the bundling of light occurs too late, resulting in a blurred image. Farsightedness is usually diagnosed at birth. The decisive factor is often a too short eyeball. Compared to nearsightedness, however, farsightedness occurs less frequently. Both visual defects can be corrected by glasses or contact lenses. However, the visual impairment may worsen in the course of life. Therefore, regular adjustment of the lenses may be necessary. If there is no pathological change in the eyes, loss of eyesight is not to be expected due to nearsightedness or farsightedness.
