What are the factors associated with myopia?
1. Is myopia related to environmental factors?
The onset and development of myopia is very closely related to the natural and reading environments.
Natural Environment: The cornea is permeable and allows for constant oxygen exchange with the outside world. 80% of the oxygen needed for corneal metabolism comes from nature. 80% of the oxygen needed for corneal metabolism comes from nature, and when the air is polluted, the polluted air can enter the eye through gas exchange. For a long time, it will affect the eyes adversely .
Light in nature is the most effective “weapon” to prevent and control myopia, the increased level of haze in the air seriously affects the role of light. So when it comes to outdoor sports, parents should choose a good time to avoid direct glare while also avoiding periods of heavy haze.
Reading environment: The teenagers' eyes are in the stage of growth and development, and they have a strong ability to regulate. The wall of the eyeball is also relatively large stretch, reading, writing and other close work, not only need to play the role of eye regulation, the two eyeballs also need to cohesion (collection function), so the extraocular muscles will exert a certain amount of pressure on the eyeballs, over time, the anterior and posterior axes of the eyeballs may become longer. Scientific studies have found that myopia increases by -3.00D diopters for every 1mm increase in the eye axis. Of course, this kind of myopia is mostly simple myopia, usually with a relatively low degree of -6.00D or less, and the onset of myopia occurs around puberty, that is, the time of the most close eye use, and the progress is relatively slow.
2. Is myopia progression associated with negative emotions?
The effect of negative emotions on the development of myopia is often overlooked. In fact, myopia and emotions interact with each other, with negative emotions exacerbating myopia and bad emotions arising from myopia.
When the infants, young children and adolescents’ adverse emotions are present, it can lead to pupil dilation, decreased photoreceptor sensitivity and vision loss.This is due to the reduced secretion of pituitary and adrenal hormones, visual conduction and visual processing in both eyes are at a low level, which directly leads to uncoordinated contraction and diastole of the lens and eye muscles, thus further aggravating myopia.
For adults, in addition to these factors, negative moods can accelerate lens aging and reduce vision.
Many young children who have significant mood swings and are prone to anger and rage are seen to have significantly faster progression of myopia.Therefore, this requires parents in daily life in addition to cultivate scientific eye habits, but also should pay more attention to the children's emotional changes, timely guidance, to develop a healthy mental state.Therefore, this requires parents in daily life in addition to cultivate scientific eye habits, but also should pay more attention to the children's emotional changes, timely guidance, to develop a healthy mental state.
3. What are other factors that influence the development of myopia?
1) Factors related to birth parameters
① Gender: Cohort studies in China have shown that girls are more likely to be myopic than boys.
② Heredity: children are more likely to develop myopia if their parents are myopic.
③ Season of birth: children born in summer are more prone to myopia, which may be related to the age of schooling.
(2) Living environment
① Rural-urban disparity: regional studies in China show that the prevalence of myopia is higher in urban than in rural areas.
② Pollution: deep atmospheric pollution will aggravate myopia.
③ Sleeping night light: sleeping with a night light on is more likely to myopia.
4. Why does myopia progress slowly in the summer but quickly in the winter?
In summer, people are more active outdoors due to long sunlight hours and strong light; while in winter, people often reduce outdoor activities due to relatively short light hours and cold weather. Daytime outdoor activities can effectively prevent myopia, so myopia grows faster in winter. In fact, it is still closely related to the sunshine time and outdoor activities.
5. What are the risk factors for the development of myopia?
(1) Early use of electronic products (TV, cell phone, iPad, etc.). The Ministry of Education suggests that children aged 0 to 3 years old should be prohibited from using electronic products, and children aged 3 to 6 years old should avoid contact with and use of electronic products as much as possible. 0 to 6 years old is a critical period for early myopia prevention and control, and parents and kindergarten teachers should exercise strict control.
The scientific researchs have found that the main effects of prolonged use of digital electronics on the eye are:
① Impact on regulation. It has been found that the adjustment lag is higher when using a video terminal (reading distance of 50cm) than when reading a paper version of a book.
②Impact on the pupil. It has been found that the pupil changes after working in close proximity, which is manifested as a delay in pupil dilation. After 4 hours of computer use, the pupil's reflex to light is delayed, and the amplitude of the near reflex is also reduced.
③ Visual fatigue. Studies have found that the use of digital electronic products, transient frequency decreased, tear film rupture time is reduced, tear secretion is reduced, resulting in the occurrence of dry eye, plus attention to fatigue.
(2) Excessive eye time. Studies have found that reading continuously for more than 30 minutes will increase the risk of myopia.
(3) Too close eye distance. Continuous, close eye use tends to induce the formation of myopia, requiring the distance between the eye and the book is not less than 33cm.
(4) Lighting too strong or too weak. If the light is too strong, sunlight irradiation of the written, will cause strong reflection of light, eye irritation, eye discomfort, difficult to see the font, on the contrary, the light is too weak, the written light is not enough, the eyes can not clearly see the font, the head will be forward to get close to the book, the above two situations are to make the eyes fatigue, excessive eye regulation or spasm and thus the formation of myopia.
(5) Decrease in outdoor activities. Research data show that for each additional hour of outdoor activity, the degree of progression of myopia is reduced by -0.17D.
(6) Sleep deprivation. As early as 1957 the top journal Science reported that persistent darkness or light affects refractive development in chicks, which actually breaks the circadian rhythm. In recent years, more and more evidence shows that circadian rhythms are related to eye growth and refractive development. But circadian rhythms are primarily a regulatory factor involving environmental light. So does sleep deprivation cause myopia? Studies have shown that sleep deprivation promotes the development of myopia.
(7) Reading in a car or while walking. Reading while walking or reading in a moving car is very bad for the eyes. Because the car is vibrating, the body is shaking, the distance between the eyes and the book can not be fixed, coupled with the lighting conditions are not good, aggravating the burden on the eyes, often so that may cause myopia.
(8) Reading on the back. Because the human eye should be maintained in a horizontal state reading books, so that regulation and collection (convergence) to achieve consistency, reduce eye fatigue. If you lie down to read, the two eyes are not in a horizontal state, the distance between the eyes and the book is not consistent, the eyes are not consistent with the line of sight up and down, left and right, the illumination on the book is not uniform, will make the eyes of the regulation of the tension and easy to move the book close to the eyes, which can make the eyes of the burden increased by 2 to 3 times over time, the formation of myopia.
(9) Dietary reasons. Preferential eating and picky eating lead to unbalanced nutrition, and eating ice-cream and other raw and cold food injures the spleen and stomach, affecting the absorption of nutrients.