Analysis of visual irritation occurs at the receptors. More precisely, it begins there. After that, there are still a lot of processes that accompany the analysis. In general, everything that happens in the human body is very interesting. And this topic is no exception. So it’s worth telling more about it.
The concepts
So, before telling where the analysis of visual stimuli takes place, I would like to touch on the concepts themselves. So, through the senses directly to the cerebral cortex, information constantly flows. This is not something that happens every second - continuously. The remaining sections of the cortex receive impulses coming from different parts of the body. And any information, as well as irritants, are analyzed carefully. This is necessary for the full activity of the human body.
So, the analysis of visual irritations occurs in the receptors, and each of their groups is sensitive to completely different information. What happens when it comes to visualization? Naturally visual, but receptors respond primarily to color and light.
After impulses appear in the receptors, they pass along the afferent neurons, through which they enter the central nervous system. And only then they get into the corresponding zone of the cortex.
Organ of vision
Everyone knows that the eye is the organ of vision in man and in any other living creature. More precisely, this is his colloquial name. In fact, it consists of an eyeball and an auxiliary device. They have their own functions. And the eyeball performs the most important, because it is in it that the peripheral section of all analyzers is located.
The pupil is the first thing I would like to draw attention to when speaking about the analysis of visual irritations. The process of light absorption occurs in the pupil. It is through him that the rays enter the eye. There is a retina, characterized by an extremely complex and fragile structure. And it is on its surface that cones and rods are located (these are photosensitive cells). And the nerve itself departs directly from the cells. It is the beginning of the conductor part of the analyzer itself.
Refraction
So, after the light rays pass through the cornea and aqueous fluid, an analysis of visual irritation begins. Occurs in the crystalline lens, and then flows into the vitreous. All this is the optical system of the eye, which refracts the rays, and then collects them already on the retina.
Also interesting is the process during which the image is analyzed. So, the rays emanating, in fact, from two parallel points, are refracted and displayed on the retina. But only upside down (in simple terms). However, then they again pass through the receptors, and already processed (inverted) information (image) enters our brain.
This is all due to the bending of the lens. Because of this, the picture turns upside down. It is important to know that the lens and the retina are extremely fragile parts of our optical system and their slightest defect can lead to a clear imbalance. Because of this, the picture may focus not only fuzzy, but even behind the retina. And this is farsightedness. When the image is focused in front of the retina, it is, accordingly, myopia.
Sticks and cones
These receptors were mentioned above. An analysis of visual irritation occurs in them too. Sticks are called receptors that are most sensitive to light radiation. For them, even dim twilight lighting can be an irritant. However, they do not react to color. That is, in what shades the objects are painted. It is the sticks that are used at the moment when a person walks along a dark street and distinguishes between the silhouettes of cars, houses and other people, but cannot answer the question: what color is maroon, blue, or black?
Cones, as you might guess, are not so sensitive to light. But thanks to them, we distinguish colors and shades. They are opposite the pupil. With age, the number of cones increases and they become stronger, this justifies the moment that a person, growing up, can distinguish more and more colors and shades.
Adaptation
This is another point that I would like to touch upon, telling about the analysis of visual irritations. Occurs in the same optical system. Adaptation is the addiction of the eye to perceive the surrounding reality at different levels of illumination. So, for example, if at night a person sits at home and then the light suddenly turns off, for some time he feels as if blind. However, after a minute or two, he will begin to distinguish the contours of objects, and then, getting used to it, he will at all begin to see what surrounds him. There is an hour to be in pitch darkness, then you can increase the sensitivity of your eyes two hundred times! Such is the specific analysis of visual irritations.
About the same thing happens in the optic nerve when a person enters a brightly lit room from the dark. And there is accommodation. This is a process in which the eyes adapt to distinguish an object at different distances.
In general, in our optical system there are a lot of processes. Of near interest is myopia and farsightedness, for example, color blindness, etc. However, these are very extensive and multifaceted topics, and they should already be discussed separately.