How does a person perceive the world around them? Eyes are the organ of vision. A person receives the most information about the world around him
with the help of sight.
Vision helps to distinguish
the color of items, their size,
shape, learn, far away
are they or close, moving
or motionless.
Age-related changes in vision
Class2
3
Decreased vision
3
3
Myopia
2-23%
2-39%
4
5
6
2
3
1
2-21%
- 25%
2-20%
7
8
9
4
4
6
1-20%
1-29%
1-23%
10a
10b
3
2
1-27%
4-37,5%
This is how a short-sighted person sees the world
To improve vision - glasses!
Rules for working with a computer:
1. The workplace should be self-contained, i.e. notconnect other devices to the computer socket.
2. The computer must be in the corner, because exactly
behind the radiation is higher than from the screen.
3.The monitor should not be exposed to direct sunlight.
rays. Working with the computer should not exceed
2 hours a day, every 30 minutes a break for
recreation.
4. The distance from the screen to the eyes is at least 50 cm.
5.In a room with computer equipment
wet cleaning should be carried out daily. Hey!
My name is Kolya, I am 12 years old and I study at 6
class. I want to introduce you to my
best friend - a computer. I am with him
I practically do not part, I play a lot,
watching movies. It takes the most
a place of honor in my room - next to
my bed. To prevent parents from seeing
whether it is turned on or not (for some reason they really do not
like my new friend), I put it
monitor to the window, and everyone else to
doors. Only one problem is the sun
interferes with playing, but that's okay. The main thing is me
I do not go outside. What for? After all, football
you can play virtually.
Hygiene rules when doing homework:
1. Homework should betake place in a specially equipped
location.
2. The light should fall from the left side.
3.The light source should only illuminate
work surface, and the lampshade should
hide the filament from the eyes.
4.The power of the light bulb in the lamp must be
not less than 60 watts.
5.The distance from the eyes to the book should be
40 cm.
It is forbidden!
It is forbidden!
It is forbidden!
To relieve fatigue - we look into the distance ...
Gymnastics for the eyes
1. Without turning your head, shift your gazeto the lower left corner, to the upper right, to
bottom right, bottom left corner.
Repeat 5 to 8 times.
2. With open eyes, slowly, to the beat
breath, smoothly draw an eight in
space horizontally, vertically.
3.With open eyes, without turning
heads, write your name in the space,
surname, first in small letters, and
then big.
Nutrition for the eyes
Take care of your eyes
Read, write only in good lighting, but remember that bright light should not enter your eyes.Make sure that the book and notebook are
at a distance of 30 - 35 cm from the eyes.
Place the book on an inclined stand while reading.
When writing, the light should fall from the left.
Do not read while lying in transport
Take care of your eyes.
If you read, write, draw for a long time,give your eyes every 20 minutes
relax: never have three eyes with your hands. So
you can put a speck in them and dangerous
microbes. Use a clean nasal
handkerchief, look out the window, into the distance, until
count to 20. Very harmful to the eyes
watch TV for a long time.
Feel free to wear glasses.
Analyzers and senses
Analyzers
Analyzers are called systems that consist of receptors, pathways and centers in the cerebral cortex. Each analyzer has its own modality, that is, the way of receiving its own information: visual, auditory, gustatory and other. Excitations arising in the receptors of the organs of sight, hearing, touch, have the same nature - electrochemical signals in the form flow of nerve impulses... The receptors are highly specialized. Each of their groups is capable of perceiving and translating into the language of signals, that is, nerve impulses, understandable to the nervous system, only a certain set of stimuli. Confusion does not occur, because each of the nerve impulses enters the corresponding area of the brain. Here, in the primary sensitive zones, the analysis of sensations takes place, in the secondary zones - the formation of images received from the senses of one modalities(for example, only from sight, or only from hearing or touch). Finally, in the tertiary zones of the cortex, images or situations are reproduced obtained from the senses of different modalities, for example, from sight and hearing.
Visual analyzer
The meaning of sight... Through the visual analyzer, a person receives the bulk of information. The objects and phenomena around us, our own body, we perceive primarily with the help of sight. Thanks to our eyesight, we learn many household and work skills, we learn how to fulfill certain rules of behavior. This means that in the knowledge of the external world for a person, vision plays a primary role. The ability to see the beauty in the surrounding nature, in the works of sculpture, architecture, painting, ballet, cinema, distinguishes an educated person.
Eye structure... The eyes are equipped with a large number of assistive devices to protect them. it brows so that sweat from the forehead does not get into the eyes. Eyelids and eyelashes protect eyes from dust. The eyelids constantly close and open (blink), evenly wetting the surface of the eye with tear fluid. Tears are formed in the lacrimal glands located in the outer part of the orbit above the eye, excess tear fluid flows into the nasal cavity through lacrimal duct... The secret of the lacrimal glands acts not only as a lubricant, but also as a disinfectant liquid. The eye has the shape of a ball and is therefore called the eyeball. This shape allows him to move within certain limits in the cavity of the bone cavity - eye socket... Eye movement is achieved by contraction six eye muscles... They are attached at one end to the wall of the orbit, the other to the eyeball.
Outside, the eye is covered with dense white tunica albuginea that surrounds the entire surface of the eyeball. The tunica albuginea connects to the mucous membrane, which covers the eyelids from the inside. In front, the tunica albuginea connects to the transparent membrane - cornea... Another shell of the eye - vascular... It is riddled with many blood vessels supplying the eye with blood. The inner surface of this shell contains a thin layer of dye, a black pigment that absorbs light rays. In front, opposite the cornea, the choroid passes into iris, which can be of different colors depending on the amount of pigment in it. It is this shell that determines the color of the eyes. There is a round hole in the center of the iris - pupil... The pupil expands or contracts depending on the amount of light falling on the eye. This is easy to see for yourself if you observe the pupil in a mirror and at the same time bring some light source, such as a lamp, to your face and move away from it. Finally, the inner wall of the eyeball is lined with a very thin shell - retina... It has a complex structure. It contains cells that are very sensitive to light - visual receptors... It is in them that the energy of light rays penetrating the eye is converted into a process of nervous excitement. And along the fibers optic nerve these nerve impulses travel to the brain.
Retina has a thickness of 0.15–0.20 mm and consists of several layers of nerve cells. The first layer of the retina is directly adjacent to the black pigment cells. This layer is formed by visual receptors - rods and cones... In the retina of the human eye, there are tens of times more rods than cones. The rods are excited very quickly by weak twilight light, but cannot perceive color. The cones are excited more slowly and only by bright light, they are able to perceive color. The rods are relatively evenly distributed over the retina. Directly opposite the pupil in the retina is yellow spot, which contains only cones. Therefore, most clearly a person distinguishes between those objects, the images of which fall directly on the yellow spot. With the help of the eye muscles, we can control the movement of the eyes and change the direction of the gaze. But always, when examining a new object, the gaze moves so that the image of parts of the object consistently falls on the macula. Long processes extend from the nerve cells of the retina. In one place of the retina, they gather in a bundle and form the optic nerve. More than a million of its fibers transmit visual information to the brain in the form of weak nerve impulses. The place on the retina where the optic nerve comes out is devoid of receptors and is called blind spot... Every student can be convinced of its existence with the help of simple experience.
Hygiene of vision. Prevention of eye diseases
Hygiene of vision... Many people develop myopia. If you follow simple rules, then in most cases this visual impairment can be prevented. It is very harmful to keep books and notebooks at a distance of 30 cm from your eyes. When we look at objects at close range, the muscular apparatus of the eye strains, the curvature of the lens changes, there is rapid fatigue and deterioration of visual perception. With constant poor lighting and improper landing, the habit of looking at everything up close is developed. As a result, myopia develops. A stay in nature, where a wide outlook is provided, is a wonderful rest for the eyes. Good lighting is essential for normal eye function. The study table should be placed closer to the window and so that the light falls on the left. A desk lamp with a 60-75 W light bulb is placed on the desktop on the left, protected by a lampshade so that the light does not enter the eyes, but illuminates only a book or notebook. Lighting that is too bright irritates the eyes and can lead to fatigue. It is harmful to read in moving vehicles, especially in poor lighting conditions. Due to the constant jolts, the book moves away from the eyes, then approaches them, then deviates to the side. In this case, the curvature of the lens increases and decreases, and the eyes turn all the time, "catching" the elusive text. As a result, vision deterioration occurs. When we read lying down, the position of the book in the hand in relation to the eyes is also constantly changing, its illumination is insufficient. The habit of reading lying down damages your eyesight.
Protect your eyes from injury. This is the most common cause of corneal opacity (leucorrhoea) and blindness. The cause of eye injuries in children is most often pranks and fights. Some guys throw sticks, stones, shoot with slingshots. All this can lead to eye injuries. In school workshops and in production facilities, students must strictly observe safety rules (use goggles, a screen, etc.). Do not blow off sawdust, shavings, as they can get into the eyes. When dust gets into your eyes, it irritates them. Dust-causing microbes can be carried along with the dust. Infection can enter the eye from dirty hands, an unclean towel, or a handkerchief. This can cause various eye diseases, for example, inflammation of the mucous membrane - conjunctivitis, which often leads to visual impairment. Therefore, your eyes must be protected from injury, from foreign objects, dust, do not rub them with your hands, wipe only with a completely clean towel or handkerchief.
Visual impairment... One of the important characteristics of vision is acuity vision. Visual acuity determines the extreme ability of the eye to distinguish fine details in the field of view. Visual acuity depends on general illumination, contrast of image details against a specific background, and other reasons. The most common visual impairments are myopia and hyperopia. The presence of these disorders is determined by the doctor when measuring visual acuity using special tables. Myopia can be congenital and acquired. With congenital myopia, the eyeball has an elongated shape. Therefore, a clear image of objects located far from the eyes does not appear on the retina, but, as it were, in front of it. Acquired myopia develops due to an increase in the curvature of the lens, which can occur with improper metabolism or impaired vision hygiene. Nearsighted people see distant objects blurry. Glasses with biconcave lenses help to ensure that sharp images of objects appear precisely on the retina. Farsightedness it is also congenital and acquired. With congenital farsightedness, the eyeball is shortened. Therefore, a clear image of objects located close to the eyes appears as if behind the retina. Acquired farsightedness occurs due to a decrease in the convexity of the lens and is most characteristic of the elderly. Farsighted people see close objects blurry, cannot read the text. Glasses with biconvex lenses help to create an image of a close object exactly on the retina.
You cannot use other people's glasses or choose glasses for yourself without a doctor's prescription. This leads to further deterioration of vision.
Auditory analyzer
Hearing value... The sense of hearing is one of the main things in human life. Hearing and speech together constitute an important means of communication between people, serve as the basis for relationships between people in society. Hearing loss can lead to behavioral problems. Deaf children cannot learn full speech. With the help of hearing, a person catches sounds that signal what is happening in the outside world, the sounds of the nature around us - the rustles of the forest, birdsong, the sounds of the sea, as well as various pieces of music. With the help of hearing, the perception of the world becomes brighter and richer.
The ear and its function... Sound, or sound wave, is an alternating rarefaction and thickening of air, spreading in all directions from the sound source. And the source of sound can be any vibrating body. Sound vibrations are perceived by our hearing organ. The organ of hearing is very complex and consists of
Outdoor,
Medium,
· Inner ear.
Outer ear comprises
Auricle,
· The ear canal.
The ears of many animals can move. This helps the animal to pick up where even the quietest sound is coming from. The auricles of a person also serve to determine the direction of sound, although they are immobile. The ear canal connects the outer ear to the next section, the middle ear. The ear canal is blocked at the inner end of the tightly stretched eardrum... A sound wave, striking the eardrum, makes it vibrate, vibrate. The higher the sound, the higher the vibration frequency of the eardrum. The stronger the sound, the more the membrane vibrates. But if the sound is very weak, barely audible, then these vibrations are very small. The minimum audibility of a trained ear is almost on the border of those vibrations that are created by the random movement of air molecules. This means that the human ear is a hearing instrument that is unique in its sensitivity. Behind the eardrum lies an air-filled middle ear cavity. This cavity is connected to the nasopharynx by a narrow passage - auditory tube... When swallowing, air is exchanged between the pharynx and the middle ear. A change in the pressure of the outside air, for example in an airplane, causes an unpleasant sensation - “ears popping”. It is due to the deflection of the eardrum due to the difference between atmospheric pressure and the pressure in the middle ear cavity. When swallowing, the auditory tube opens and the pressure on both sides of the eardrum is equalized. In the middle ear there are three small bones connected in series with each other:
Hammer,
Anvil
· Stirrup.
The hammer, connected to the tympanic membrane, transfers its vibrations first to the incus, and then the amplified vibrations are transmitted to the stirrup. In the plate separating the middle ear cavity from the inner ear cavity, there are two windows, constricted by thin membranes. One window oval, a stirrup "knocks" on it, another - round... The inner ear begins behind the middle ear. It is located deep in the temporal bone of the skull. The inner ear is a system of labyrinths and convoluted channels filled with fluid. There is an organ of hearing in the labyrinth - snail... This is a spirally twisted bone canal, which in humans has two and a half turns. The vibrations of the foramen ovale membrane are transmitted by the fluid that fills the inner ear. And she, in turn, begins to vibrate with the same frequency. By vibrating, the fluid irritates the auditory receptors located in the cochlea. The cochlear canal is bisected along its entire length by a membranous septum. Part of this septum consists of a thin membrane - membranes... There are perceiving cells on it - auditory receptors... Fluctuations in the fluid filling the cochlea irritate individual auditory receptors. They generate impulses that are transmitted along the auditory nerve to the brain.
Auditory perception... In the brain, there is a distinction between the strength, height and nature of the sound, its location in space. We hear with two ears, and this is of great importance in determining the direction of the sound. If sound waves arrive simultaneously in both ears, then we perceive the sound in the middle (front and back). If sound waves arrive a little earlier in one ear than in the other, then we perceive the sound either to the right or to the left.
Similar information.
Radobolskaya L.Yu., Radobolskiy S.I.
VISUAL HYGIENE
HOW CORRECT TO READ?
It is imperative that the light was correct during the reading. This will save your eyes from overexertion. The light source when reading should be located above and behind the reader in such a way that the light falls from over the shoulder. It is forbidden to read if the light is coming into the face. The lighting of the room where the person is reading should be quite bright. It is impossible to read in the twilight, as this deteriorates vision. The desktop should be positioned so that the window or other light source is on the left. An artificial light source, for example, a table lamp, must necessarily be covered with a shade, since direct light rays would otherwise cut the eyes. When reading with a table lamp on, it is also better to leave the main lighting on - this will create a smooth transition from less intense light to more intense.
It is harmful to read in a driving car, as the text is at different distances from the eyes as a result of shaking. In vision hygiene, it is very important to maintain the correct distance between the eyes and the text, which should be at least thirty centimeters.
HOW IS IT CORRECT TO WORK WITH A COMPUTER?
We recommend doing a few simple exercises to relieve eye strain while using your computer. During operation, the computer monitor should be at least arm's length away. In addition, the monitor should be positioned on the desktop so that, looking up, you can see all objects in the room. After forty minutes of working at the computer monitor, you need to take a break, do light exercises, for example, frequent blinking, during which the eyes relax and moisturize the secretions of the lacrimal glands.
EYE GYMNASTICS COMPLEX
Horizontal eye movements: right-left. Movement of the eyeballs vertically up and down. Circular movements of the eyes: clockwise and in the opposite direction. Intense eye clenching and unclenching at a fast pace. Diagonal eye movement: squint your eyes to the lower left corner, then look up in a straight line. Likewise in the opposite direction. Reduction of the eyes to the nose. To do this, put your finger to the bridge of your nose and look at it - your eyes will easily "connect". Frequent blinking of the eyes. Eye work "at a distance". Go to the window, carefully look at a close, well-visible detail: a branch of a tree growing outside the window, or a scratch on the glass. You can stick a tiny paper circle on the glass. Then direct your gaze into the distance, trying to see objects as far away as possible.
PREVENTION
To prevent myopia, you need to expose yourself to ultraviolet rays. In the event of a shortage of ultraviolet rays, a violation of the metabolism of phosphorus and calcium occurs in the body. For this reason, the adaptive capacity of the eyes is reduced. Under the influence of the sun's rays, vitamin D, which is in the cells of the skin, becomes active and normalizes the correct absorption of phosphorus and calcium compounds in the body.
THE RIGHT DIET
Balanced nutrition plays a huge role in eye hygiene, which should include the required amount of vitamins, in particular "eye" vitamins A and D. Vitamin D is included in products such as beef liver and sea herring, egg yolk and natural butter. Vitami A is extremely important for vision, as it is responsible for the eye's ability to see at dusk. With a deficiency of this vitamin, visual acuity is upset, the skin loses its tone, becomes vulnerable to inflammatory processes. Vitamin A is found in abundance in cod liver, cream and chicken eggs. There is also such a substance as provitamin A, called carotene. Carotene is necessary in the human body for the synthesis of vitamin A. There is a lot of carotene in carrots and bell peppers, rose hips and onions, apricots and lettuce.
The work was prepared by: pupils of grade 11 "a"
Sirotina Svetlana Laskova Aksinya
Volzhsky 2013
importance of adherence
hygiene of vision
1) Definition of vision hygiene
2) Factors affecting vision
3) Proper nutrition for good vision
4) Rules for working at the computer
5) 5 golden rules
6) Conclusion
Everyone is obliged to protect their eyes
Hygiene of vision Is a set of measures aimed at preserving and maintaining good vision, prevention of many eye diseases.
Hygiene of vision
When working with high eye strain, it is necessary to periodically give rest to the eyes. You can also massage the eyes. Highly
it is useful to look at nature admiring the greenery, flowers. You can look into the distance, into the endless depth of the sky. This not only gives rest to the eyes, but also calms the nervous system, relieves stress.
Factors affecting vision
1) Rational nutrition
2) Reading hygiene
3) Compliance with the rules of landing and lighting
4) Compliance with the rules when watching TV and working at the computer
Rational nutrition: in which foods vitamins "live"
Vitamin A - fish, seafood, apricots, carrots, tomatoes, etc.
Vitamin B1 - rice, vegetables, poultry, etc.
Vitamin B2 - milk, apples, wheat grains, etc.
Vitamin C - rose hips, bell peppers, black currants, etc.
Work rules for
computer
1) Choose the right posture. Namely: straight
opposite the screen, the top of the monitor at eye level or slightly below.
2) Maintain an eye-to-monitor distance -
3) Choose a convenient
4) The height of the seat of the chair (chair) must be
so that the hands on the keyboard are horizontal.
5) Take 15-20 minutes breaks every hour.
6) Watch your breath: it should be
smooth, without delay.
7) Exercise as often as possible for
Slide 2
- Ophthalmology is a science that studies the anatomy, physiology of the organ of vision, diseases related to the organ of vision, as well as the structure of blindness.
- The objectives of ophthalmology are to minimize the number of blind and visually impaired people.
According to the WHO, there are 42 million blind and visually impaired people in the world. Moreover, an increase in this indicator is observed annually, and the growth is 3-6% per year.
Slide 3
- One of the important characteristics of vision is visual acuity.
- Visual acuity determines the extreme ability of the eye to distinguish fine details in the field of view.
- Visual acuity depends on general illumination, contrast of image details against a specific background, and other reasons.
- The most common visual impairments are myopia and hyperopia.
- The presence of these disorders is determined by the doctor when measuring visual acuity using special tables.
Visual impairment
Slide 5
In myopic eyes, the image is focused in front of the retina.
Slide 6
Near-sighted people find it difficult to see the numbers of public transport routes, read road signs, and also distinguish other objects from a distance.
At the same time, the myopic can see well at close range.
- In the vicinity
- In the distance
Slide 7
Causes of myopia
Excessive visual work at a close distance from the subject (no rest for the eyes and in poor lighting);
Hereditary predisposition, expressed in the structural features of the eyeball and metabolism in it;
Weakened sclera that does not offer adequate resistance to overgrowth of the eye
Insufficiently developed accommodative eye muscle, which is responsible for the "attunement" of the lens at different distances;
Overstrain of a weakened muscle.
Slide 9
In farsighted eyes, the image is focused behind the retina.
Slide 10
In people suffering from farsightedness, the accommodative muscle is constantly tense, therefore, visual fatigue and headache often occur.
Slide 11
Poor near vision;
Poor distance vision (with large degrees of hyperopia);
Increased eye fatigue when reading;
Eye strain during work (headaches, burning eyes);
Strabismus and lazy eyes in children;
Frequent inflammatory eye diseases (blepharitis, barley, chalazion, conjunctivitis)
Hyperopia symptoms
Slide 12
If you are worried about the symptoms of hyperopia, then you need to undergo a complete ophthalmological examination to find out the features of the pathology and choose a method of vision correction.
Loading ...