Why is vision gradually declining?

The causes of myopia are very complicated and there are many influencing factors. The main factors can be roughly divided into genetic factors, environmental factors and nutritional factors. 1. Genetic factors: According to a large number of survey data, the unanimous conclusion is that high myopia is related to heredity, but there is a great difference between myopia below moderate level. The genetic type of high myopia, the conclusion of most survey data is autosomal recessive inheritance. So parents and children can't be nearsighted at the same time. Heredity is often influenced by the objective environment, that is, living conditions, which makes it mutate and increases the complexity of heredity. 2. Environmental factors: environmental factors are mainly close work and bad working environment, which is the oldest theory. Although there are still some disputes, from a large number of domestic and foreign investigation and research reports, it has been recognized that heredity and environment are the main causes of myopia, and it is pointed out that environmental conditions are the objective factors that determine the formation of myopia. However, under the influence of close reading or close work, why does myopia occur? There is no consensus on this, and there are mainly the following theories: (1) Accommodation theory: Myopia mostly occurs in teenagers, and because teenagers have particularly strong eye accommodation ability and strong adaptability to close-up work and study, they are not easy to get tired at close range. However, if the ciliary muscle is excessively tense for a long time, the ciliary muscle will be tired or even convulsed, resulting in accommodative myopia. If it is not eliminated in time, it will become irreversible true myopia. Or affect the elongation of the eyeball axis through other ways. (2) Convergence theory: In the adjustment of close work, it is necessary to strengthen the convergence function of both eyes at the same time, which can lead to the pressure of eye muscles on the eyeball and the extension of the eyeball axis. (3) Theory of environmental adaptation: The eyeball in early childhood is small, mostly hyperopia. With the increase of age, the eyeball grows and reaches an upward state. In this development process, people read too much at close range and their eyeballs become nearsighted to meet the needs of this adjustment. This theory has been opposed by many people, but it is very plastic in the development period and has an important impact on the development of myopia. Other theories will not be introduced. It should be mentioned that external factors such as light, reading posture, contrast, small blur, too close distance and long reading time will all affect the above factors. 3. Nutritional constitution theory: According to some data analysis, the lack of trace elements such as cadmium, strontium and zinc and the weakness of constitution can also affect the occurrence of myopia, but the ways in which these factors affect the occurrence of myopia are different. In a word, it can be seen from the above that myopia can be caused by many factors, both external factors and internal physical factors, rather than a single factor. Vision is roughly divided into three degrees. From the clinical symptoms: within two years, the degree is less than 200 degrees, the vision is greater than 0.5, and most of them are pseudomyopia; The course of disease is more than four years, the degree is more than 400 degrees, and the vision is less than 0.2, mostly true myopia; In between is half true and half false myopia. Judging from the age of netizens, the poor eyesight protection will continue to increase. You can wear glasses or do laser surgery, and pay attention to eye hygiene. How to prevent myopia? To prevent myopia, we should pay attention to the following points: ① To cultivate the correct posture of children reading and writing, the distance between eyes and books should be about 30 cm. (2) When reading and writing, the light should be moderate, not too strong or too dark, and the light should be irradiated from the left front to avoid the shadow of the hand blocking the line of sight. (3) Reading time should not be too long. Every 40 ~ 50 minutes, you should rest for 10 ~ 15 minutes, close your eyes or look far away for a few minutes or do eye exercises to prevent eye fatigue. Don't read too small or illegible books and newspapers, and don't write too small. ⑤ Educate children to correct unreasonable eye habits, such as lying on the table, reading or writing with their heads tilted, reading in bed, reading at meals, reading in bright or dim street lights and moonlight, reading in a moving car, walking, etc. These bad habits will make the eyes excessively tired and reduce the acuity of vision. Preventive measures should also be taken from the following aspects: (1) It is forbidden to marry close relatives. (2) Pay attention to eye care. The prevention of myopia advocates an early word, which is to start with school-age children. (1) Schools and parents should pay special attention to children's learning lighting to meet the requirements (50 ~ 100 m candle). Specifically, if a 25-watt ordinary light bulb is used, the illumination at a distance of half a meter is about 50 m candle, and so on. (2) to prevent overuse of eyes, that is, not to make the muscles inside and outside the eyes too tired or in a state of tension for a long time. ③ Strengthen eyesight training and insist on eye exercises. ④ Prevention of TV myopia. (3) Strengthening physical exercise and improving physical fitness can reduce and slow down the occurrence of myopia, especially outdoor sports. It is also one of the best health care methods for the eyes to let children overlook the countryside with fresh air and broad vision and appreciate the mountains and rivers of the motherland. (4) Pay attention to nutritional supplements, especially vitamin B and mineral supplements, because they are necessary for eye development and functional progress. Can prenatal and postnatal care reduce myopia in children? It is reasonable for children to blame their parents for myopia. For a long time, many surveys have confirmed that the occurrence of myopia has a certain familial nature. Parents are short-sighted, children are short-sighted, parents are short-sighted, children are short-sighted, one parent is short-sighted, and children are short-sighted. Therefore, children's myopia is closely related to their parents. There are also many children with eye deformities, strabismus, ametropia and amblyopia. Because of parents' improper marriage, pregnancy is not good. Some parents rush around for the diagnosis and treatment of their children's eye diseases, silently bear the inner pain and pay an infinite price; There are also a few parents who relentlessly give up the treatment of their children and have no regrets. What's more, they applied for another birth because of their children's eye diseases ... We really feel sorry and guilty for these ignorant, ignorant and heartless parents, and we care more about those victimized children. Here we want to warn these parents, to know now, why at the beginning! In order to benefit future generations, eugenics is unstoppable. How to prevent myopia among teenagers Source: Beijing 777 Health Network Click: 123 Update Time: May 22, 2005 In recent years, the incidence of myopia among teenagers has been increasing year by year, and the age of onset is moving down. Teenagers' myopia is usually caused by long-term close use of eyes, which leads to excessive adjustment and convergence of eyes, and the pressure of extraocular muscles on eyeballs increases, which leads to blurred distant objects and decreased far vision over time. The prone age of myopia is 7 ~ 17 years old, and the peak age of myopia is 10 ~ 15 years old. This is because the physiological characteristics of teenagers' eyeballs and some external factors, such as bad learning environment, bad eye habits, physical fitness, etc., can easily cause abnormal eyeball development, which leads to myopia. Therefore, prevention of myopia must be taken seriously from an early age. So, what preventive measures are there? 1. It is not advisable to use your eyes at close range for too long. You should rest every 45 ~ 60 minutes 10 ~ 15 minutes. When resting, you should overlook the window or do outdoor activities to fully relax the eye accommodation muscles. 2. The light should be moderate when you use your eyes at close range. Too strong or too weak light when using eyes at close range is an important factor causing myopia. Therefore, at night or in a dark environment, it is best to use 40 ~ 60W incandescent lamps for lighting and put them in the upper left corner of the desk. This is because incandescent lamps have soft light, good color rendering performance, and the eyeballs are easy to adapt to prevent eye fatigue caused by too strong or too dark light. 3. Close your eyes correctly. Close eye posture is another factor that affects the incidence of myopia. When using eyes at close range, the height ratio of tables and chairs should be appropriate, and books should be placed 30cm away from eyes. Bad eye habits, such as reading while driving, lying in bed or working at a desk, will increase the adjustment burden and convergence frequency of the eyes, and increase the pressure of extraocular muscles on the eyeball, especially for primary and secondary school students, whose eyeball is in a developing stage with a wide ball wall. Long-term bad eye posture can easily lead to abnormal eyeball development and myopia. 4. Take an active part in physical exercise to enhance physical fitness. Physical fitness is also closely related to the occurrence of myopia in adolescents. For example, children with malnutrition, acute and chronic infectious diseases, physical weakness, partial eclipse or gluttony for sweets tend to be nearsighted. Therefore, in daily life, teenagers' diet should be reasonably matched with meat and vegetables, not partial eclipse, and ensure the completeness and balance of various nutrients. On weekdays, we should strengthen physical exercise, such as running, doing radio exercises, playing ball and kicking shuttlecock. In addition, eye exercises are also a good way to prevent myopia and self-care. You can do eye exercises between reading and writing to relieve eye fatigue. (The author is the deputy chief physician of Shanghai Institute of Ophthalmology.) Eye movement can improve vision. In middle age, the left eye vision is 0.3, and the right eye vision is 1.0. After more than 20 years of early and late eye movement exercise, my binocular vision in the last 3 years is 1.5. The method is: sit on the bed or chair, turn your eyes to the left for 3 times, then look straight ahead for a while (meditation for 5 times), turn your eyes to the left for 3 times, and look straight ahead for a while. Turn it twice every morning and evening, without interruption, and stick to it for a long time, that is, see the effect. (Grain Rain) vision care, an old friend, is old, but his eyesight is still good. Q: When I wash my face every morning (the water temperature should be higher to avoid scalding my skin), I first soak the towel and hot compress my eyes and temples for about a minute or two, for decades. When my wife died, I was in Lacrimosa all day, thinking that I was blind, and my pain was unimaginable. So after applying this method every day, I feel very comfortable with my eyes. This is also a blessing. (Lu Jingyi) Chrysanthemum Eye 2003-6- 16 For friends who often have to face computers, the health of their eyes will be greatly threatened. Some people drink a lot of water before going to bed to moisten dry eyes, but the next morning, their eyes will swell. Here is a popular method for friends, which can effectively protect eyes and avoid the embarrassment caused by eye edema-smearing clean cotton around eyes with chrysanthemum water can quickly eliminate edema. Chrysanthemum is very effective in treating dry eyes, fatigue and blurred vision. China has known since ancient times that chrysanthemums can protect eyes. Therefore, in addition to smearing your eyes, you may wish to soak some chrysanthemum tea often. If you can drink three or four cups of chrysanthemum tea every day, it will not only make the symptoms of eye fatigue disappear, but also help to restore your vision. There are many kinds of chrysanthemums. People who don't know the doorways often choose chrysanthemums with big white flowers. Actually, this is a misunderstanding. The real choice should be small, ugly and yellow. It is best to drink chrysanthemum tea without tea, just soak the dried chrysanthemum in water or boil it. Hot drinks in winter and iced drinks in summer all taste good. My neighbor's aunt, who is over 60 years old, used to see things in a blur. A few years ago, her old mother told her a method: look forward, turn your eyes three times, and then turn them up and down three times. Do eye exercises after you finish, and insist on doing them twice a day. She persisted for several years, and now she can wear a needle without glasses and read books and newspapers. (Su Zhang) Chrysanthemum soaked in water to treat pinkeye.