Abstract: in the relaxed state of adjustment, the parallel light is focused in front of the retina after passing through the ocular refractive system, which is called myopia. Myopia is also called myopia, because this kind of eye can only see near, not far.
nowadays, myopia is a high incidence disease. Many primary school students wear glasses, and many bad habits will lead to myopia. Therefore, how to prevent myopia has become a very important topic. So do you know the causes of myopia and what are the methods to prevent myopia? Let’s have a look.
in the relaxed state, the parallel light is focused in front of the retina after passing through the ocular refractive system, which is called myopia. Myopia is also called myopia, because this kind of eye can only see near, not far. When the eye is at rest, the parallel light from an infinite distance passes through the refraction of the refractive system of the eye, gathers into a focus in front of the retina, and forms an unclear image on the retina. The far vision is significantly reduced, but the near vision is still normal. There are many methods of
to prevent myopia. Any measure conducive to reducing visual fatigue and relaxing eye adjustment can be tried. Of course, other ways can be explored, but they should be scientific, reasonable, beneficial and harmless. The common preventive measures for
are as follows:
. First, the light should be sufficient. The reflective light should avoid the comfortable light of
, which can get good visual information. Too strong or too dark light will bring adverse effects to the eyes. Therefore, the desk where teenagers usually read should have a side lamp device, which aims to reduce reflection and reduce eye damage.
2. The continuous reading time should not be too long.
teenagers read and write, watch TV and use the computer for several hours without rest. Some students even go to bed late at night, which not only affects their health, makes the eyes overburdened, and is easy to cause regulatory or functional myopia, that is, pseudomyopia. Moreover, it will also make the extraocular muscles produce pressure on the sclera tissue of the eyeball wall, increase the intraocular pressure and congest the intraocular tissue. Therefore, it is appropriate for students to take a break every 50 minutes.
III. sit upright and at a moderate distance.
don’t bend over or read on the table, let alone lie in bed and read on your side. The distance between eyes and books should be kept at 30-35 cm, the distance between body and desk should be kept at about 10 cm, and the angle between books and desks should be kept at 30-45 degrees. If the book is placed horizontally on the desktop, you should lower your head slightly forward when reading, so it is easy to move the book close to your eyes and increase the burden on your eyes by 2-3 times, resulting in fatigue of neck muscles and nape, and unconsciously tilt forward, which will lead to decreased vision in the long run.
IV. watch less TV and use less computers.
try to reduce contact with televisions, computers, game consoles and other electrical equipment that radiate to human eyes, because the X-rays radiated by the picture tube can consume a lot of rhodopsin in the retina and significantly reduce vision. The computer had better choose LCD to reduce the damage of electromagnetic wave to eyes. Students who often play video games are more likely to damage their eyesight, and low vision students who play video games since childhood can’t even correct their eyesight with glasses. The reason is that the function of retina and macula has been damaged.
v. sleep should be sufficient, pay attention to eye hygiene,
work and rest time should be regular, and sleep should be sufficient. Lack of sleep will lead to conjunctival congestion, increased secretion, photophobia and tears, eye soreness and other conjunctival and keratitis. Try to avoid eye damage caused by wind, sand, smoke, ultraviolet, infrared, chemicals and medical supplies. Personal hygiene shall be kept clean. Personal items such as towels, washbasins and handkerchiefs shall be used by special personnel, and other items shall not be used as much as possible, so as to avoid cross infection, eye diseases and vision loss.
VI. pay attention to the dietary structure, and the nutritional intake should be balanced. The nutritional intake of
should be balanced. Partial eating or excessive intake of sugar and protein, resulting in the lack of trace elements such as zinc, calcium and chromium, is not conducive to visual health. The prevention method is to eat more vegetables, fruits, liver, fish and other foods
7. You can’t read
when driving or walking. Some teenagers like to read while walking or in the walking carriage, which is very bad for their eyes, because the carriage is shaking, the body is shaking, and the distance between their eyes and the book can’t be fixed, In addition, poor lighting conditions increase the burden on the eyes. Often, this may cause myopia.
(1) Genetic factors. Myopia has been recognized to have a certain genetic tendency, especially for high myopia. But for general myopia, this tendency is not very obvious. Those with genetic factors have an earlier age and more than 600 degrees. However, those with high myopia have no family history. High myopia belongs to autosomal recessive inheritance, and general myopia belongs to multifactorial genetic disease.
(2) Developmental factors. Infants are hyperopia because their eyeballs are small, but with the increase of age, the ocular axis also gradually lengthens, and the development is normal after the age of 6. If they are over developed, they form myopia, which is called simple myopia, which usually starts in school age and is lower than 600 degrees. They stop developing around the age of 20. For example, they progress quickly in childhood, and progress more rapidly at the age of 15 ~ 20 Quickly, and then slow down. This kind of myopia is often higher than 600 degrees, up to 2000 ~ 2500 or 3000 degrees. This kind of myopia is called high myopia or progressive myopia or pathological myopia. This kind of myopia can degenerate in old age, so the vision can gradually decline, and the vision can not be corrected with glasses. But very few are congenital, Myopia
at birth (3) Environmental factors. People engaged in writing or other close work have more myopia, and there are also more myopia among young students. Moreover, the prevalence rate has increased significantly since the fifth and sixth grades of primary school. This phenomenon shows that the occurrence and development of myopia are closely related to close work. Especially the eyeballs of teenagers are in the stage of growth and development, The adjustment ability is very strong, and the extension of the ball wall is also better than that of the ball wallThe adjustment and collection function during close work such as reading makes the internal rectus muscle exert a certain pressure on the eyeball, and the intraocular pressure increases accordingly. With the continuous increase of work, the frequency and time of adjustment and collection also gradually increase. The ciliary muscle and extraocular muscle are often in a state of high tension. Excessive exertion of the adjustment function can cause ciliary muscle spasm, Thus causing temporary vision loss. However, vision may improve or completely recover after rest or use of ciliary muscle erosion agent. Therefore, some people call this myopia functional myopia or pseudomyopia