Traditional medicine

Presentation on the topic visual analyzer. Structure and functions of the eye

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The visual analyzer, its structure and functions, the organ of vision. Author of the presentation: Pechenkina V.A. Teacher, Municipal Educational Institution “Gymnasium No. 10”, Pushkino

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Analyzers These are systems of sensitive nervous formations that perceive and analyze various external and internal stimuli.

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Visual analyzer The visual analyzer consists of the eyeball, auxiliary apparatus, pathways and visual cortex of the brain.

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1.Where is the eye located, what auxiliary organs protect our eyes? 2. How many muscles can the eyeball move? Organ of vision - eye

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The eyeball and the auxiliary apparatus of the eye. The eyeball is located in the orbit of the skull. The auxiliary apparatus of the eye includes the eyelids, lacrimal apparatus, muscles of the eyeball, and eyebrows. Motility of the eye is provided by six extrinsic muscles...

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Diagram of the structure of the eye Fig. 1. Scheme of the structure of the eye 1 - sclera, 2 - choroid, 3 - retina, 4 - cornea, 5 - iris, 6 - ciliary muscle, 7 - lens, 8 - vitreous body, 9 - optic disc, 10 - optic nerve, 11 - yellow spot.

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Sclera The sclera is the protein shell - the outer dense connective tissue membrane of the eye, which performs a protective and supporting function.

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The main substance of the cornea consists of a transparent connective tissue stroma and corneal bodies. In front, the cornea is covered with multilayered epithelium. The cornea (cornea) is the anterior most convex transparent part of the eyeball, one of the light-refracting media of the eye.

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The choroid of the eye is the middle layer of the eyeball. Plays an important role in metabolic processes, providing nutrition to the eye and removing metabolic products. It is rich in blood vessels and eyeball pigment (in Fig. 2)

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The iris (iris) is the thin, movable diaphragm of the eye with a hole (pupil) in the center; located behind the cornea, in front of the lens. The iris contains varying amounts of pigment, which determines its color - “eye color”. The pupil is a round hole through which light rays penetrate inside and reach the retina (the size of the pupil changes [depending on the intensity of the light flux: in bright light it is narrower, in weak light and in the dark it is wider].

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Detect constriction and dilation of the pupil. - Look into the eyes of your desk neighbor and note the size of the pupil. -Close your eyes and shade them with your palm. -Count to 60 and open your eyes. -Observe changes in pupil size. How can we explain this phenomenon?

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The face of the eye is a transparent body located inside the eyeball opposite the pupil; Being a biological lens, the lens is an important part of the light-refracting apparatus of the eye. The lens is a transparent biconvex round elastic formation,

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The lens is strengthened inside the eye by special very thin ligaments. Replacing the lens of the eye.

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Retina of the eye Retina (lat. retina) is the inner membrane of the eye, which is the peripheral part of the visual analyzer.

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Structure of the retina: Anatomically, the retina is a thin membrane, adjacent along its entire length from the inside to the vitreous body, and from the outside to the choroid of the eyeball. There are two parts in it: the visual part (receptive field - the area with photoreceptor cells (rods or cones) and the blind part (an area on the retina that is not sensitive to light). Light falls from the left and passes through all layers, reaching the photoreceptors (cones and rods), which transmit the signal along the optic nerve to the brain.

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How does the eye see? The path of rays from an object and the construction of an image on the retina (a). Scheme of refraction in a normal (b), myopic (c) and farsighted (d) eye. The eye, like any converging lens, produces an inverted image on the retina, real and reduced.

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Ecology and visual hygiene it is better to use fluorescent lamps, it does not strain the eyesight so much

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Myopia Myopia (myopia) is a vision defect (refractive error) in which the image falls not on the retina, but in front of it. The most common cause is an enlarged (relative to normal) eyeball in length. A rarer option is when the refractive system of the eye focuses the rays more strongly than necessary (and, as a result, they again converge not on the retina, but in front of it). In any of the options, when viewing distant objects, a fuzzy, blurry image appears on the retina. Myopia most often develops during school years, as well as during studies in secondary and higher educational institutions, and is associated with prolonged visual work at close range (reading, writing, drawing), especially in poor lighting and poor hygienic conditions. With the introduction of computer science in schools and the spread of personal computers, the situation became even more serious.

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farsightedness Farsightedness (hyperopia) is a feature of the refraction of the eye, consisting in the fact that images of distant objects at rest of accommodation are focused behind the retina. At a young age, if farsightedness is not too high, using accommodation voltage, you can focus the image on the retina. One of the causes of farsightedness may be a reduced size of the eyeball on the anterior-posterior axis. Almost all babies are farsighted. But with age, in most people this defect disappears due to the growth of the eyeball. The cause of age-related (senile) farsightedness (presbyopia) is a decrease in the ability of the lens to change curvature. This process begins at the age of about 25 years, but only by the age of 40-50 years it leads to a decrease in visual acuity when reading at the usual distance from the eyes (25-30 cm).

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What is the structure of the eye? Place signs. sclera Vitreous body retina lens pupil Choroid Oculomotor muscles iris cornea

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Screening test on the topic “Visual analyzer” Select the correct answer 1. The transparent part of the outer shell of the eye is: a) retina b) Cornea c) Iris 2. The cornea of the eye performs the function of: a) nutrition b) transmission of sunlight c) protection 3. The pupil is located: a) in the lens b) in the vitreous c) in the iris 4. The membrane of the eye containing rods and cones is: a) tunica albuginea b) retina c) choroid 5. Rods are: a) twilight light receptors b) parts of the vitreous body c) color vision receptors 6. Cones are: a) twilight light receptors b) parts of the cornea c) receptors that perceive color 7. Night blindness is caused by dysfunction of: a) rods b) cones c) lens 8 In weak light, the pupil: a) reflexively narrows b) reflexively expands c) does not change 9. The retina of the eye: a) protects from mechanical damage b) supplies the eye with blood c) converts light rays into nerve impulses 10. If light rays are focused behind the retina. , this causes: a) myopia b) farsightedness c) blindness

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Test yourself! 1. The transparent part of the outer shell of the eye is: a) retina b) Cornea c) Iris 2. The cornea of the eye performs the function of: a) nutrition b) transmission of sunlight c) protection 3. The pupil is located: a) in the lens b) in the vitreous body c) in the iris 4. The membrane of the eye containing rods and cones is: a) tunica albuginea b) retina c) choroid 5. Rods are: a) twilight light receptors b) parts of the vitreous c) color vision receptors 6 Cones are: a) receptors for twilight light b) parts of the cornea c) receptors that perceive color 7. Night blindness is caused by dysfunction of: a) rods b) cones c) lens 8. In low light the pupil: a) reflexively narrows b. ) reflexively expands c) does not change 9. The retina of the eye: a) protects from mechanical damage b) supplies the eye with blood c) converts light rays into nerve impulses 10. If light rays are focused behind the retina, this causes: a) myopia b) farsightedness c ) blindness

The importance of vision Thanks to the eyes, you and I receive 85% of the information about the world around us; they are the same, according to calculations by I.M. Sechenov, give a person up to 1000 sensations per minute. The eye allows you to see objects, their shape, size, color, movements. The eye is able to distinguish a well-lit object with a diameter of one tenth of a millimeter at a distance of 25 centimeters. But if the object itself glows, it can be much smaller. Theoretically, a person could see a candle light at a distance of 200 km. The eye is capable of distinguishing between pure color tones and 5-10 million mixed shades. Complete adaptation of the eye to the dark takes minutes.

The iris (iris) is the thin, movable diaphragm of the eye with a hole (pupil) in the center; located behind the cornea, in front of the lens. The iris contains varying amounts of pigment, which determines its color “eye color”. The pupil is a round hole through which light rays penetrate inside and reach the retina (the size of the pupil changes [depending on the intensity of the light flux: in bright light it is narrower, in weak light and in the dark it is wider].

The lens is a transparent body located inside the eyeball opposite the pupil; Being a biological lens, the lens is an important part of the light-refracting apparatus of the eye. The lens is a transparent biconvex round elastic formation,

Photoreceptors signs rods cones Length 0.06 mm 0.035 mm Diameter 0.002 mm 0.006 mm Number 125 – 130 million 6 – 7 million Image Black and white Colored Substance Rhodopsin (visual purple) iodopsin location Predominant in the periphery Predominant in the central part of the retina Macula – a collection of cones, the blind spot – the exit point of the optic nerve (no receptors)

Structure of the retina: Anatomically, the retina is a thin membrane, adjacent along its entire length from the inside to the vitreous body, and from the outside to the choroid of the eyeball. There are two parts in it: the visual part (the receptive field - the area with photoreceptor cells (rods or cones) and the blind part (the area on the retina that is not sensitive to light). Light falls from the left and passes through all the layers, reaching the photoreceptors (cones and rods) ), which transmit the signal along the optic nerve to the brain.

Farsightedness (hyperopia) is a feature of the refraction of the eye, consisting in the fact that images of distant objects at rest of accommodation are focused behind the retina. At a young age, if farsightedness is not too high, using accommodation voltage, you can focus the image on the retina. One of the causes of farsightedness may be a reduced size of the eyeball on the anterior-posterior axis. Almost all babies are farsighted. But with age, in most people this defect disappears due to the growth of the eyeball. The cause of age-related (senile) farsightedness (presbyopia) is a decrease in the ability of the lens to change curvature. This process begins at about 25 years of age, but only by 4050 years of age leads to a decrease in visual acuity when reading at the usual distance from the eyes (2530 cm). Colorblindness Up to 14 months in newborn girls and up to 16 months in boys, there is a period of complete color blindness. The formation of color perception ends by the age of 7.5 years in girls and by 8 years in boys. About 10% of men and less than 1% of women have a color vision defect (blindness between red and green or, less commonly, blue; there may be complete color blindness)

Visual

analyzer

Objective of the lesson:

Study the features of the structure and operation of the visual analyzer

1 option

Option 2

1. What cells form the basis of the nervous system:

1. Which part of the brain does the cerebral hemisphere belong to?

b) neurons

b) the brain

The path along which a nerve impulse passes from its place of origin to the working organ:

2. What are convolutions:

c) reflex arc

a) folds of the cerebral cortex

3.What parts of the nervous system are divided into by location:

3.What parts of the nervous system are divided into according to their functions:

d) central and peripheral

c) somatic and vegetative

4. Which part of the brain is responsible for coordinating movements?

4. The spinal cord performs in our body:

c) reflex and conductive

b) cerebellum

5. Name the parts of the brain:

5. Name the lobes that form the cerebral hemispheres:

Frontal
Parietal
Occipital
Temporal

Large hemispheres
Cerebellum
Intermediate
Midbrain
Medulla oblongata

The meaning of vision

We live with you among beautiful colors, sounds and smells. But the ability to see most affects our perception of the world.

A person perceives approximately 70% of information from the surrounding world through the organ of vision.

Auxiliary apparatus

Brows
Eyelids and eyelashes
Lacrimal gland and lacrimal canaliculi
Oculomotor muscles
Nerve
Blood vessels

Iris "active", provides transition to slide 4

The structure of the eyeball

Has a spherical shape
It consists of an inner core covered with three membranes: the outer one is fibrous, the middle one is vascular, and the inner one is reticular.
Lens

Physical education minute

Your eyes are a little tired. Close your eyes tightly and count to 5, then open them and count to 5 again. Repeat 5-6 times. This exercise relieves fatigue, strengthens the eyelid muscles, improves blood circulation and relaxes the eye muscles.

Z fastening topics

1. How many membranes does the eyeball have:

2. Which of the membranes of the eyeball gives it color:

a) fibrous membrane

b) retina

c) vascular (iris)

3. Place in the correct sequence:

Visual cortex

optic nerve

retinal receptors

1_________________________

2_________________________

3_________________________

4. Establish a correspondence between the concept and its characteristics:

iris -

cornea -

a) can contract and expand

b) posterior part of the fibrous membrane

c) responsible for eye color

d) convex - concave lens

HOMEWORK: read pp. 72-77, draw a drawing of an eye on pp. 74-75 creative task: - make up 1 – 2 puzzles on the topic “Visual analyzer” - solve a situational problem: Driver Ivanov, who hit a purebred dog with his car, claims that he I haven't seen it on the road at all. Is he honest in his testimony? Explain the answer. - explain the saying from a biological point of view: “In the dark, all cats are gray”

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Why do they say that the eye looks, but the brain sees?

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Structure of the organ of vision

The organ of vision is the most important of the senses, providing a person with up to 95% of information.

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Functions of parts of the eye

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The principle of the eye is similar to that of a camera.

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Optical system and light-receiving part of the eye

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Retina

The light-receiving part is the retina. It contains light-sensitive cells - visual receptors, about 130 million rods, providing black and white vision, and about 7 million cones, providing information about color.

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Structure of the retina

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The retina consists of several layers of cells:

The outer layer adjacent to the choroid is a layer of black pigment cells. This layer absorbs light, preventing its scattering and reflection;
three layers of cells: bipolar, ganglion, then their axons, uniting into the optic nerve;

Next comes the layer containing rods and cones.

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The maximum number of cones is located in the retina on the optical axis of the eye, opposite the pupil, this area is called the macula.
In the place where the optic nerve leaves the eyeball, there are no receptors in the retina - a blind spot.
The maximum number of rods is located on the periphery of the eye.
The rods contain the visual pigment rhodopsin; a small amount of light is enough to decompose it.
In cones, under the influence of light, iodopsin decomposes, but more light is needed to excite the cones.

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What happens on the retina

The light flux passes through:

Cornea
Iris
Pupil
Lens
Vitreous body
Retina

Retinal image is reduced and inverted

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Light hits photosensitive cells;
A photochemical reaction occurs (rhodopsin breakdown);
The potential of photoreceptors changes;
Excitement occurs;
Along the optic nerve, excitation goes to the visual center of the cerebral cortex;
In the cortex, the final analysis of excitation, image discrimination and sensation formation occurs.

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As a result

The brain sees, not the eye.
Vision is a cortical process and depends on the quality of information received from the eye.
That is why the eye looks and the brain sees.

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Slide captions:

Structure and functions of the membranes of the eye. Visual hygiene.

There should be a reflection of happiness in the eyes of beautiful and big ones” (G. Alexandrov) “I believe! These eyes don't lie. After all, how many times have I told you that your main mistake is that you underestimate the value of human eyes. Understand that the tongue can hide the truth, but the eyes can never! You are asked a sudden question, you don’t even flinch, in one second you control yourself and know what needs to be said to hide the truth, and you speak very convincingly, and not a single wrinkle on your face moves, but, alas, alarmed by the question oh the truth from the bottom of the soul jumps into the eyes for a moment, and it’s all over. She's been spotted and you've been caught! (Film "The Master and Margarita") "But by the eyes - you can’t confuse them both up close and from afar. Oh, the eyes are a significant thing. Like a barometer. You can see everything - who has great dryness in their soul, who about what he can poke in the ribs with the toe of his boot, and who is afraid of everyone” (Mikhail Afanasyevich Bulgakov. “The Heart of a Dog” “The eyes are the mirror of the soul” (V. Hugo)).

“A wonderful world, full of colors, sounds and smells, is given to us by our senses” (M.A. OSTROVSKY)

Her eyes are like two fogs, Half a smile, half a cry, Her eyes are like two deceptions, Covered in the mist of failure. A combination of two mysteries. Half delight, half fear, a fit of mad tenderness, anticipation of mortal torment. When darkness comes and a thunderstorm approaches, Her beautiful eyes flicker from the bottom of my soul. Nikolay Zabolotsky

How many sense organs does a person have? - Five: vision, smell, hearing, taste, touch. It turns out that we also have a sixth sense - a sense of balance.

Human sense organs.

Brain centers that control the functioning of the senses.

What are analyzers? Physical, chemical physiological mental process. process process. Sensation irritation excitation pathways Stimuli Sensory organ (receptors) Center in the cerebral cortex

Analyzers are physiological systems that provide perception, conduction and analysis of information from the internal and external environment and form specific sensations. Sensation is a direct reflection of the properties of objects and phenomena of the external world and internal environment that affect the senses. An analyzer is a system consisting of receptors.

Receptors are specialized nerve endings that convert stimuli into nervous excitation. Information is information about objects and phenomena of the environment. Illusions are distorted, erroneous perceptions. Aesthesiology is a branch of anatomy that studies the structure of the sense organs.

Visual analyzer

* The eye is the peripheral part of the visual analyzer. * The eye is often compared to a camera, which contains a casing (cornea), lens (lens), diaphragm (iris) and light-sensitive film (retina). It would be more appropriate to compare the human eye with an analogue of a complex computer cable device, since we look with our eyes and see with our brains. * The eye has an irregular spherical shape, approximately 2.5 cm in diameter.

* Two eyeballs are securely hidden in the sockets of the skull. The organ of vision consists of the auxiliary apparatus of the eye, which includes the eyelids, conjunctiva, lacrimal organs, extraocular muscles and fascia of the orbit, and the optical apparatus - the cornea, aqueous humor of the anterior and posterior chambers of the eye, lens and vitreous body. * The retina, optic nerve and visual pathways transmit information to the brain, where the resulting image is analyzed. * The lens has an amazing property - accommodation. * Accommodation is the ability of the eye to clearly see objects at different distances due to changes in the curvature of the lens.

External structure of the organ of vision The eye is covered in front by the upper and lower eyelids. The outside of the eyelids is covered with skin, and the inside with a thin membrane - the conjunctiva. In the thickness of the eyelids in the upper part of the orbit there are lacrimal glands. The fluid they produce enters the nasal cavity through the lacrimal canaliculi and lacrimal sac. It also moisturizes the mucous membrane of the eye, so the surface of the eyeball is always moist. The eyelids slide freely over the mucous membrane, protecting the eye from adverse environmental factors. Under the skin of the eyelids are located the muscles of the eye: the orbicularis muscle and the levator of the upper eyelid. With the help of these muscles, the palpebral fissure opens and closes. Eyelashes grow along the edges of the eyelids, performing a protective function. The eyeball moves with the help of six muscles. They all work in concert, so eye movement - moving and turning in different directions - occurs freely and painlessly.

Sclera, cornea, iris. Internal structure of the organ of vision. The eyeball consists of three membranes: outer, middle and inner. The outer layer of the eye consists of the sclera and cornea. The sclera (white of the eye) - the durable outer capsule of the eyeball - acts as a casing. The cornea is the most convex part of the anterior part of the eye. It is a transparent, smooth, shiny, spherical, sensitive shell. The cornea is, figuratively speaking, a lens, a window to the world. The middle layer of the eye consists of the iris, ciliary body and choroid. These three sections make up the vascular tract of the eye, which is located under the sclera and cornea. The iris (anterior section of the vascular tract) - acts as the diaphragm of the eye and is located behind the transparent cornea. It is a thin film painted in a certain color (gray, blue, brown, green) depending on the pigment (melanin) that determines the color of the eyes. People living in the North and South tend to have different eye colors. Northerners mostly have blue eyes, southerners have brown eyes. This is explained by the fact that during the process of evolution, people living in the Southern Hemisphere produce more dark pigment in the iris, as it protects the eyes from the adverse effects of the ultraviolet part of the spectrum of sunlight.

Pupil, lens, vitreous body Internal structure of the organ of vision. In the center of the iris there is a black round hole - the pupil. Rays passing through it and the optical system of the eye reach the retina. The pupil uses muscles to regulate the amount of light entering, which contributes to the clarity of the image. The diameter of the pupil can vary from 2 to 8 mm depending on the lighting and the state of the central nervous system. In bright light the pupil constricts, and in dim light it dilates. Along the periphery, the iris passes into the ciliary body, in the thickness of which there is a muscle that changes the curvature of the lens and serves for accommodation. In the area of the pupil there is a lens, a “living” biconvex lens, which is also actively involved in the accommodation of the eye. Between the cornea and the iris, the iris and the lens, there are spaces - chambers of the eye, filled with a transparent, light-refracting liquid - aqueous humor, which nourishes the cornea and lens. Behind the lens is a transparent vitreous body, which belongs to the optical system of the eye and is a jelly-like mass.

Retina The internal structure of the organ of vision. Light entering the eyes is refracted and projected onto the back surface of the eye, called the retina. The retina (photosensitive film) is a very thin, delicate and extremely complex nerve formation in structure and function. Figuratively speaking, the retina - a kind of window into the brain - is the inner shell of the eyeball. The retina is transparent. It occupies an area equal to approximately 2/3 of the choroid. The photoreceptor layer, which includes rods and cones, is the most important cell layer in the retina. The retina is heterogeneous. Its central part is the macula, which contains only cones. The macula is yellow in color due to the yellow pigment it contains and is therefore called the macula macula. Rods are most common on the peripheral parts. Closer to the yellow spot, in addition to the rods, there are cones. The closer to the macula macula, the more cones there are, and the macula itself contains only cones. In the center of the visual field, we see with the help of cones, this part of the retina is responsible for distance visual acuity, and in the periphery, rods are involved in the perception of light. The human retina is arranged in an unusual way - it seems to be upside down. One possible reason for this is the location behind the receptors of a layer of cells containing the black pigment melanin. Melanin absorbs light passing through the retina, preventing it from being reflected back and scattered inside the eye. Essentially, it plays the role of black paint inside the camera, which is the eye.

The human eye contains two types of light-sensitive cells (receptors): highly sensitive rods, responsible for twilight (night) vision, and less sensitive cones, responsible for color vision. In the human retina there are three types of cones, the maximum sensitivity of which falls on the red, green and blue part of the spectrum, that is, corresponds to the three “primary” colors. They provide recognition of thousands of colors and shades.

Visual analyzer Perception of visual sensations The visual analyzer is a set of nerve formations that provide the perception of the size, shape, color of objects, and their relative position. In the visual analyzer: - the peripheral section consists of photoreceptors (rods and cones); - conduction section - optic nerves; - central section - visual cortex of the occipital lobe. The visual analyzer is represented by the perceptive department - the receptors of the retina of the eye, the optic nerves, the conduction system and the corresponding areas of the cortex in the occipital lobes of the brain.

Visual hygiene. Our eyes provide a unique opportunity to perceive the world around us. But they are vulnerable and tender, so we must take care of them. There are rules that, if followed, help maintain eye health for a long time. It is necessary to read in sufficient, good lighting. The eyes should not be overstrained. Lighting is considered good if: - the lamp is located above and behind - the light should fall from behind the shoulder; - when the light is directed directly into the face, you cannot read; - the brightness of the lighting should be sufficient; if it is twilight around and the letters are difficult to distinguish, it is better to put the book aside; - the desktop in daylight should be positioned so that the window is on the left; - the table lamp should be on the left in the evening; - the lamp must be covered with a lampshade so that the light does not fall directly into the eyes. You should not read in transport when it is moving. After all, due to constant shocks, the book approaches, moves away, and deviates to the side. Our eyes probably don’t like this kind of “training.”

Do not hold the book closer than 30 cm from your eyes. If you look at objects too close, the eye muscles become overstrained, quickly causing fatigue. When going to the beach or for a walk in the bright sun, do not forget to wear sunglasses. After all, your eyes can also get sunburned. With such a burn, the conjunctiva of the eye swells and turns red, the eyes itch and hurt, vision deteriorates - objects around seem blurry. If the sunlight is not bright, you can take off your glasses. Watching TV for a long time or working at a computer for a long time also negatively affects our eyes. It is better to sit further away from the TV, at least two meters away. But the distance to the monitor should be no less than the length of an outstretched arm. When working at a computer, it is very useful to take breaks every 40-45 minutes and... blink! Yes, exactly blink. Because it is a natural way to cleanse and lubricate the surface of the eye. To ensure that good vision lasts for many years, you need to eat right. Vitamins A and D are especially beneficial for the eyes. Vitamin A is found in foods such as cod liver, egg yolks, butter, and cream. In addition, there are foods rich in provitamin A, from which the vitamin itself is synthesized in the human body. Provitamin A is found in carrots, green onions, sea buckthorn, sweet peppers, and rose hips. Vitamin D is found in pork and beef liver, herring, and butter.

Eye diseases There is an old Turkmen proverb: “A person does not die from eye diseases, but no one will come to inquire about his health.” We are taught to take care of our eyes from childhood, but in the fast pace of life we forget about the good advice of parents, teachers and doctors, and, unfortunately, we do not have a clear idea of how to preserve our vision for many years. This is due to the characteristics of our upbringing, living conditions, family traditions, etc. Blepharitis is inflammation of the edges of the eyelids. Eyelid abscess is purulent inflammation of the eyelids. Allergic conditions. In this case, there is itching in the eye area, swelling of the soft tissues, and there may be redness and lacrimation.

Eye diseases Cataract. This is a disease of the lens. It mainly occurs in old age and is associated with clouding of the lens, which is caused by a violation of its structure. Color blindness (color blindness). This disease causes an inability to distinguish certain colors. Twitching of the eyelid. This is one of the types of nervous tics. It can be associated with stress, lack of sleep, etc. Farsightedness or hypermetropia is especially common in older people. With it, light rays are focused as if behind the retina. Surrounding objects appear blurry and lack contrast. Myopia or myopia can be congenital or acquired. With it, light rays are focused in front of the retina. Good visual acuity is only possible at close range, and distant objects are seen blurred.

Run the test. 1. Match the sense organs and the stimuli that they perceive: Sense organ Stimulus: 1. Organ of vision A. Red traffic light. 2. Organ of hearing B. Smooth silk 3. Organ of taste B. Bitter medicine 4. Organ of smell D. Fire siren 5. Organ of touch E. Perfume 2. Arrange the parts of the analyzer in order. a) associative zone of the cerebral cortex, b) receptors, c) pathways 3. Match the analyzers with their representations in the brain: 1) occipital zone; a) Auditory analyzer: 2) parietal zone; b) Visual analyzer; c) Taste analyzer Conduct a self-test and evaluate your work according to the following criteria: “3 points” - completed all tasks correctly. “2 points” – completed 2 tasks correctly. “1 point” – completed 1 task correctly

Run the test. 1.Which of the following is included in the composition of the eyeball? A) External rectus muscle of the eyeball B) Ciliary muscle C) upper and lower eyelids. 2. What are the cone cells in the retina responsible for? A) Twilight and daylight vision B) Twilight and color vision C) Daytime and color vision 3. What is myopia? A) Myopia; B) Farsightedness; B) Astigmatism 4. The “blind spot” is: A) the place where the cones are concentrated; B) the internal space of the eyeball; C) the place where the optic nerve exits. 5. When reading a book in the evening, the light should: A) be directed directly into the face; B) fall from the left; C) is not needed at all.

Crossword 1. A small hole in the center of the iris, which can reflexively expand or contract with the help of muscles, allowing the required amount of light into the eye. 2. A biconvex transparent formation located behind the pupil. 3. Convex-concave lens through which light penetrates into the eye 4. Inner membrane of the eye. 5. Nerve cell processes or specialized nerve cells that respond to specific stimuli. 6. Twilight light receptors. 7. Visual impairment, in which the lens loses its elasticity and nearby objects become blurry. 8. Depression in the skull. 9. An auxiliary device that protects the eye from dust. 10. Organ of vision. 11. Transparent and colorless body, filling the inside of the eye. 12. The middle part of the choroid, which contains the pigment that determines the color of the eyes. 13. The exit point of the optic nerve, where there are no receptors. 14. One of the auxiliary apparatus. 15. Outer shell. 16. Protein shell. 17. Visual impairment, when the image of an object is focused in front of the retina and is therefore perceived as blurry. 18. Receptors capable of responding to colors. 19. Protective formations from sweat flowing from the forehead. 20. A complex system that provides analysis of irritation and controls motor and labor activity of a person.

Resources used. Eyesurgery.surgery.su / eyediseases / cureplant.ru/index.php/ bolezni-glaz travinko.ru/ stati / bolezni-glaz le-cristal.ru/ gigiena-zreniya /