Children will habitually “squint” when watching TV or the blackboard; when reading or playing with a cell phone, they will involuntarily approach the target; after a long period of time, they will also occasionally rub their eyes with their hands or blink frequently. …… Are parents aware of these signs?
In this regard, the People’s Daily, in conjunction with the National Health and Health Commission, invited Wang Ningli, director of the Ophthalmology Center of Peking Tongren Hospital, director of the Public Health Ophthalmology Branch of the Chinese Preventive Medical Association, and president of the Ophthalmology Branch of the Chinese Physicians’ Association; Guo Xin, director of the Beijing Municipal Center for Disease Control and Prevention; and Li Yan, director of the People’s Hospital of Peking University, to popularize the popular knowledge of the prevention and control of myopia and to guide the families and children and adolescents to do a good job of myopia prevention and control.
0 to 3 years old is the critical period of visual development
As to when to pay attention to children’s eyesight and prevent myopia, Li Yan said: “In the process of human development, from birth to 3 years old is the biggest change of refractive error in a lifetime, and most of the newborn babies have low hyperopia of 150 degrees to 200 degrees. Along with the growth, the lens is gradually flat, the eye axis gradually lengthened to the preschool stage, and gradually complete the orthokeratology process. 0 to 3 years old is the most critical period of visual development, 0-12 years old is the sensitive period.”
“With the popularity of electronic products, the adverse stimulation of electronic screens, resulting in children nowadays orthokeratization process completed in advance, during which some children began to appear myopia and gradually deepen. 3-year-old children’s eyes initial development is completed, the period between the ages of 3 and 6 years old is a more important stage of development. We recommend basic vision screening for children starting at age 3.” Li Yan said that children at this age can effectively cooperate with vision screening with guidance.
At the same time, Liyan explains the child’s vision condition in terms of age groups. He said, “Generally the normal vision of a 3-year-old child is 0.5, a 4-year-old child is 0.6, a 5-year-old child is 0.8, and a 6-year-old child can reach 1.0. If a child’s vision is found to be lower than that of a child of the same age after the vision check at the age of 3, he or she has to undergo further examinations, such as dilated pupil photometry of eye axes, corneal topography examination, etc.”
“The elementary school stage from 6 to 12 years old is the key prevention and control stage for myopia prevention and control. After the child began to read and write homework, affected by prolonged close eye use, low light illumination, if this time do not pay attention to eye hygiene, it is easy to occur myopia. 12 to 18 years old during secondary school, the child’s degree of eye use reaches its peak, to face the pressure of the midterm and college entrance exams, the need to focus on the change in visual acuity, pay attention to the speed of myopia deepening.” Li Yan said.
“Therefore, according to the spirit of the National Health Commission and other eight departments issued the “comprehensive prevention and control of myopia in children and adolescents implementation program”, the establishment of refractive files, regular records of children’s visual acuity, the length of the eye axis, corneal curvature, and other refractive status conditions, and closely follow up on the development of children’s visual health, so as to achieve early discovery, early intervention, early treatment.” He said.
Be aware of the six precursors to myopia
According to Li Yan, “There are six main precursors to myopia.
First, squinting. When squinting, the eyelids cover part of the pupil, reducing diffuse light and minimizing the effects of astigmatism, thus temporarily increasing and improving visual acuity.
Second, blinking. Frequent blinking relieves myopia to some extent and increases visual clarity.
Third, rubbing the eyes. When children have trouble seeing a target, they often rub their eyes with their hands in an attempt to see better.
Fourth, frowning. Frowning in the hope of making both eyes ‘harder’ as a way to improve vision.
Fifth, wrenching the eyes. A few children, when unable to see a distant target, often forcefully pull the skin of the outer corner of the eye outward to achieve the same effect as tilting the head or squinting.
Sixth, head tilting. Often occurs is tilting the head to watch TV, tilting the head can reduce the interference and influence of some diffuse light, some children will even develop the habit of tilting the head.
If there are any of the above symptoms, I hope that parents can take their children to the ophthalmology department of a regular medical institution to rule out myopia.”
On how to effectively prevent myopia from occurring, he said, “At present, the mechanism of myopia is still not completely clear. It is widely believed that myopia is the result of a combination of genetic and environmental factors. Among them, myopia has a strong relationship with factors such as outdoor exposure and close eye use. Children should focus on factors such as the use of electronic products, lighting and illumination, reading and writing postures, etc. in their daily studies. It is recommended that outdoor activities for more than two hours a day, online learning time for primary school students not more than 20 minutes each time, secondary school students not more than 30 minutes each time, writing homework to maintain ‘one foot, one fist, one inch’, that is, look at the close distance to one foot, the body away from the desk one fist, hands away from the tip of the pen one inch.”
Li Yan also suggests, “Children whose schools are close to their homes are advised to walk to and from school. If far from home, it is recommended to consider getting off the bus two stops ahead of time, and then walk, with specific reference to the Guidelines for Prevention and Control of Nearsightedness in Children and Youth during Home Quarantine for Infectious Disease Outbreaks. Children who are already nearsighted should go to a professional medical institution in time, but also according to the doctor’s treatment advice, scientific correction, follow-up observation.”
Maintaining Proper Reading and Writing Habits Families Need Study Tables and Chairs
Appropriate desks and chairs can protect your eyesight. How can parents determine whether the desks and chairs meet the requirements when allocating learning desks and chairs at home that match their children’s height?
Guo Xin said: “inappropriate desks and chairs, both affect the eye sight distance, but also due to sitting posture is not correct to increase the risk of children suffering from spinal curvature, but also increase the learning fatigue, learning efficiency and a series of subsequent problems. At home, parents configure desks and chairs, need to pay attention to three points.
First, the study of special desks and chairs, can not be replaced with other tables and chairs. For example, the dining table is usually high, dining chairs and ordinary chairs are either too high or too low; and if you sit on the bed, it will be low and soft.
Secondly, refer to the “height range table for each model of desks and chairs for primary and secondary school students” (GB/T3976-2014), prepare adjustable desks and chairs, and the desk and chair models will be different for different heights of children. Due to the different proportions of the child’s height, parents in the reference range table must be adapted to the situation. For example, after the adjustment, the child sits on a chair, stool, keep the thighs and calves perpendicular to 90 degrees; at the same time, the back is straight, the upper arms down, elbows below the desktop 3 to 4 centimeters. To meet this requirement, the manual desk and chair match the child’s height. If the desk is not adjustable, it can be adjusted according to the principle.
Third, after parents provide their children with appropriate desks and chairs, they should also remind their children to maintain correct reading and writing postures, such as keeping the shoulders relaxed, the upper back extended, the upper arm and forearm at a 90-degree angle, the wrist should be relaxed, and breathe regularly. There is also the posture of holding a pen, some children can not do the hand away from the tip of the pen an inch, and some other children even have to get the tip of the pen. So with the desk and chair, parents also have to watch their children more carefully in general.”
Create a good visual environment Four measures should be taken at home
In addition, Guo Xin also said: “In schools, there is a big action is the visual environment, including lighting lighting environmental conditions, while at home should pay attention to the following four points.
First, when placing a desk, pay attention to make the long axis of the desk and the window perpendicular. When studying during the day, the light should come in from the opposite side of the writing hand. For example, if you write with your right hand, the light should come in from the left side; if you write with your left hand, the light should come in from the right side. When natural light is low at night, use the room overhead light in preference; if light is still insufficient, supplement it with a reading and writing desk lamp. The average illuminance value of the desktop can be determined by using an illuminance meter according to the Methods of Lighting Measurement, and the value should not be less than 300 lux. If you do not have an illuminance meter at home, you can download the appropriate software on your cell phone. There is also a high limit on the value, which should not be too low or too strong.
Secondly, when you read at night, you can’t just have a desk lamp, but also the ceiling light of the room. Desk lamps should be placed in front of the opposite side of the writing hand, the color temperature does not exceed 4000K, this color temperature reading and learning, will make the child’s state of mind calm, improve learning efficiency. When using color temperature adjustable desk lamp, the night should be adjusted to the color temperature below 4000K. Color temperature is not adjustable, and higher than 4000K reading and writing desk lamp, not recommended for use at night.
Again, bare lamps without shades should not be used for study lighting, nor should glass panels or items that tend to produce glare be placed on the desk. Some families press a glass plate on their writing desk, which we do not recommend.
Finally, parents are advised to learn to read product manuals when shopping for lamps. If the family room ceiling lights and reading and writing desk lamps, do not meet the requirements of the relevant health standards or product standard requirements, we recommend that parents replace them in a timely manner, to create a good visual environment for children.”
Whether or not to wear lenses when studying with low myopia needs to be analyzed on a case-by-case basis.
For low myopia children with glasses, reading, writing homework to wear the problem, Li Yan said: “low myopia refers to 300 degrees of myopia, reading, writing homework to wear glasses, need to be analyzed on a case-by-case basis. The human eye in the near, need to adjust to see the words on the book, this process is the human eye lens directly involved. The lens is like a convex lens, when looking close, the lens becomes convex, increasing the refractive power to see closer more clearly. The reading distance that people are generally accustomed to is 33 to 40 centimeters. In order to see the words in a book clearly, for a reading distance of 33 centimeters, the human eye needs 3 D (diopter) of accommodation.”
“But people like to be lazy, 33 centimeters of reading distance, many people will use 2.5 D of adjustment can see clearly, it will cause the actual use of the adjustment force and the theoretical value of the difference, in medicine called ‘adjustment hysteresis’, which leads to the location of the clearest image is in the back of the retina, such refractive This refractive state is extremely unfavorable to the control of myopia progression. When looking at the near place, binocular vision axis will occur convergence process is called collection, collection function is in the prescription and wear lenses need to be considered in the process of the problem.” Li Yan said.
“In recent years, research has found that myopic patients are not over-adjusted, but under-adjusted, with reduced adjustment sensitivity and more pronounced adjustment lag. Therefore, from a clinical point of view, interventions should start with improving the accommodation and accommodation sensitivity and reducing the accommodation lag.” Li Yan also said, “The position in which both eyes look at something is called eye position, and this is also something that should be carefully considered during the prescription process. The general population is completely orthoptic eyes are very few, the eyes more or less there will be some degree of internal hidden oblique or external hidden oblique, see far and near is not quite the same, which is also to be considered in the process of prescription and wear glasses. All of the above, to go to the regular hospital to find optometrists to judge, need to check the binocular visual function specific indicators to determine.”