Abstract
This paper focuses on human vision and considers the various physiological and psychological bases of the system. It includes elements ranging from the structure of the human eye to an explanation of how each part of the organ performs a certain action. Ultimately, this analyzes how a person perceives the world around and what role the visual function plays in the process of remembering. The article will cover the issues of the physiological structure, functions of the organ and its physiological foundations, and psychological (cognitive-perceptual) underpinnings of the system are considered. The paper pays attention to deciphering color and how the eye is connected to the cognitive mind and perception of the surrounding world.
Introduction
When it comes to the perception of the world, as a rule, the focus is on the optical system and its functions. The eye is a unique ability that humanity possesses and receives with the help of it the main layer of information. Unlike the structure of this organ in animals, in the human body the eye can be considered as one of the most complex organs. Therefore, the topic of how a person sees covers both physiological aspects and psychological visual perception as well as its connection with the brain. The eye is directed to receive sensory information, which forms a vital picture of the surrounding reality in the head. The elements of the visual system include: the sensory organ, the eye, and the central nervous system (CNS). They contain photoreceptor cells responsible for detecting and reproducing optical information. The optical system is responsible for the interpretation of visible light in the process of mental image establishment and perception. Thus, the article discusses both the physiological and psychological underpinning of the view by considering the structure of the organ, its function and obtaining and forming a picture of the world.
Physiological Underpinnings
Structure
The human visual system consists of sensory organs and certain parts of the central nervous system that capture and process visible light. This process is responsible for the ability to see, feel light and receive monocular images (Chu et al., 2018). The sensory organ is the eye, which collects and notes information received through light. In addition, the eye has its own structure, which includes the sclera, cornea, pupil, iris, conjunctiva, retina with ganglion cells, and fovea. The optic nerve and the optic chiasm are responsible for delivering impulses from the retina to the brain.
The eyeball has three layers: outer (fibrous), middle (vascular) and inner (known as the retina). The outer shell, that is, the sclera, consists of dense connective tissue through which light rays do not pass (Garrity, 2022). Muscles of the eye are attached to the tissue, providing its movement. The sclera refers to the white part of the eye, the main substance of which is collagen. In addition, the sclera includes the cornea, the structure of which is translucent. It has a large number of nerve endings that provide sensitivity, although there are no blood vessels.
The shape of the cornea can be described as round and slightly convex, which ensures the correct refraction of the incoming light rays. In addition, people have significantly different eye color, from dark, almost black to light blue (Garrity, 2022). This is because the iris of each individual contains a different amount of pigment. Accordingly, a small amount of it gives light shades of the eyes, while a high pigmentation is responsible for a darker color.
At the same time, the conjunctiva and a transparent membrane covering the sclera enter the cornea, performing the function of protecting the pupil and anterior posterior chamber. The anterior chamber of the eye is located between the cornea and the lens (Gaspar et al., 2019). The connecting function of the anterior and posterior chambers is performed by the iris and pupil. Moreover, the pupil is described as an automatic diaphragm that contracts and expands with the help of the muscles of the iris. This allows one to adjust the amount of light flux, depending on the lighting around. In addition, behind the lens is the vitreous body, followed by the retina and choroid.
Function
The functions of vision include central, peripheral, binocular vision, light perception, color perception. The central perception is characterized by the ability to clearly distinguish details and is perceived with a yellow spot located in the central part of the retina. Its main characteristic is the level of visual acuity, which determines the state of the visual apparatus, the presence of a pathological process (Chu et al., 2018). The definition of visual acuity can be attributed to the ability to determine two different points with a minimum distance between them. It is important to note that this is a moving value that can change with a person’s age. By older age, vision may decrease due to the appearance of diseases of the retina, optic nerve and visual centers.
With regard to peripheral vision, it performs the function of distinguishing objects located on the side of the right angle of view. In addition, it gives a person the opportunity to see objects in the dark and move freely in space. Binocular vision allows an individual to simultaneously see any object or image with both eyes (Gaspar et al., 2019). In particular, this is due to the structure of the human skull, in which the eyes are in the same frontal and horizontal planes. Furthermore, the fields of view of both eyes shift and this type of vision gives a person a three-dimensional picture in three dimensions. Moreover, the binocular view helps to determine the distance to objects.
In the functions of vision, one can distinguish such phenomena as light perception and color perception. Light perception makes it possible to perceive rays of glare and determine the degree of their brightness (Ponforder et al., 2019). The rest of the functions cannot be realized without this, since even with the loss of vision, the reaction to light disappears last. The sensitivity of the eye is completely dependent on how well the retina is preserved and to what extent it contains a light-sensitive substance. In addition, the structure of the visual-nervous apparatus influences the sharpness of perception.
Color vision is defined as the ability of the human eye to distinguish colors, which is conducted by sensitivity to levels of radiation in the visible spectrum. Groups of colors depend on the wavelength of radiation: long-wave, medium-wave and short-wave. At the same time, the whole spectrum of the variety of shades that are distinguishable to the eye occurs due to the mixing of red, green and blue. Color signals are widely used in everyday life and are extremely common in various fields (Ponfonder et al., 2019). People see them in traffic signs, road traffic, advertising and many other things that attract attention. However, with some diseases or birth defects, this function may be lost. An individual may lose the perception of one of the three primary colors. In this case, the vision of other shades also changes, since in any of them there is a different amount of the lost color.
Psychological Underpinnings
Cognitive-Perceptual
Vision affects the cognitive-perceptual development of a person in various areas, forming and maintaining the psychological foundations. One such area is attention, which can improve or deteriorate with visual perception (Fraser, 2018). The ability to focus is vital for learning and visual perception dispels environmental factors that interfere with this process. At the same time, poor vision, on the contrary, distracts from the review of the topic.
In addition, the acquisition of knowledge requires any individual to make eye contact when consuming information on paper. Lack of visual skills can be a problem that hinders reading comprehension. Since vision is the main way to obtain new information, data and knowledge, this can significantly slow down the ability to quickly learn. Finally, vision affects a person’s perception of the world around him (Fraser, 2018). Good vision forms a clear picture, which allows you to accumulate experience and interests. In addition, it plays a role in the formation of personality and the allocation of one’s own characteristics. Thus, high visual acuity and color perception help a person to freely navigate in space and enjoy the beauties of the place. While a person with poor eyesight is deprived of this function to some extent, which affects their attitude towards the world.
Conclusion
In conclusion, it is worth mentioning that. that the human visual apparatus is distinguished by the complexity of the structure. The eyeball distinguishes three shells, each of which performs its own functions. With diseases or congenital defects, the individual partially or completely loses the ability to see. In addition, the functions of the visual apparatus include color and light perception, peripheral, central and binocular vision. From the point of view of psychology, visual acuity affects attention, the ability to gain knowledge and accumulate individual experience.
References
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Fraser, B. (2018). Cognitive disability aesthetics: Visual culture, disability representations, and the (in) visibility of cognitive difference. University of Toronto Press.
Garrity, J. (2022). Structure and Function of the Eyes. MSD Manual, 3(6), 1-8. Web.
Gaspar, P., Almudi, I., Nunes, M. D., & McGregor, A. P. (2019). Human eye conditions: insights from the fly eye. Human Genetics, 138(8), 973-991. Web.
Pondorfer, S. G., Terheyden, J., Heinemann, M., Wintergerst, M. W., Holz, F. G., & Finger, R. P. (2019). Association of vision-related quality of life with visual function in age-related macular degeneration. Scientific reports, 9(1), 1-7. Web.