Children’s eyesight: ametropia

Parents are always worried that their children are using their eyes excessively and affecting their eyesight. They are thinking about how to negotiate with their children with wisdom and courage, or how to arrange outdoor activities with time and effort.

It is true that children’s eyesight problems need to be paid full attention to, but the first thing to do is to know the children’s eyesight before they can be targeted. Otherwise, they may be wrong about [book gentleman] and [computer gentleman]. Today, let’s talk about the main causes of eyesight and children’s poor eyesight. Children with eyesight less than 1.0 must not be normal? Vision is the ability of human eyes to distinguish the fine structure of objects. In medicine, vision can be divided into naked eye vision and corrected vision: naked eye vision is the vision that everyone has. Correct vision, It refers to the vision that can be achieved after wearing glasses or surgery. People are not born to see everything clearly. Newborns can only see the movement of objects in front of them. With the stimulation of the external environment, The visual system develops rapidly and the eyesight gradually improves. Under normal circumstances, the eyesight of children aged 3-5 years old can reach 0.5-0.7, and that of children aged 5-7 years old can reach 0.7-0.9. The eyesight development of school-age children over 7 years old has been basically completed. Thus, children’s eyesight less than 1.0 is not necessarily abnormal, but should be judged according to the actual age. Poor eyesight is caused by [book monarch] and [computer monarch]? Due to the changes in modern education, life and entertainment modes, Myopia shows a trend of younger age, There is a high incidence among school-age children, Therefore, many people think that children have poor eyesight, It is caused by watching too much computer and TV. This is only half right. The main reason for children’s poor eyesight is not only myopia, And farsightedness and astigmatism. Normally, Eye adjustment relaxes, Distant parallel light passes through the layers of the eye, Just focusing on the retina, This condition is emmetropia. Myopia is when parallel light is focused in front of the retina. Most of them are caused by too long eyeballs, The longer the eyeball is, The deeper the degree of myopia. Hyperopia is when parallel light is focused behind the retina. For a variety of reasons, Including congenital short eyeball or acquired hypoplasia. People are mostly farsighted in infancy, This is normal, As you get older, The degree of hyperopia gradually decreased, Until you face it squarely. Astigmatism is the refraction of parallel light through the eyeball. The image is not in a focus. Most astigmatism is congenital. The main causes of poor eyesight in preschool children are hyperopia and astigmatism. School-age children are more myopic, Some children may also have astigmatism. Myopia is closely related to excessive close eye use, Reading, writing, computers and mobile phones all belong to the way of using eyes at close range. Long time or poor posture are indeed risk factors for myopia. Hyperopia and astigmatism have nothing to do with using eyes at close range. Poor eyesight ≠ amblyopia often has parents who think that children’s poor eyesight is amblyopia. Is eyesight so easy to become [weak]? In medicine, Amblyopia refers to the development of vision, The corrected vision is still lower than that of the corresponding age (0.5 for 3-5 years old, 6-7 years0.7, Over 7 years old 0.8), Or binocular vision is different, Showing a difference of two or more lines on the visual chart. Simply put, Long-term inability to see clearly is easy to cause amblyopia. Only the naked eye vision is lower than the corresponding vision standard, If the corrected vision after optical correction is within the normal range, Not amblyopia. Generally speaking, binocular hyperopia (≥ 5.00 D) or astigmatism (≥ 2.00 D) is easy to cause amblyopia, and large difference in binocular power is also a risk factor for amblyopia. Early detection and treatment of amblyopia are expected to restore normal corrected vision, but if amblyopia is not found until adolescence or adulthood, treatment is quite difficult. How to correctly evaluate children’s vision? Can’t rely on visual chart alone because children often can’t clearly express whether the vision is blurred, so it is very important to evaluate children’s eyesight, especially for children over 3 years old, it is best to check their eyesight regularly. Doctors suggest that it is best to check it once a year, if myopia is possible, it should be checked once every six months. However, it is not enough to check their eyesight alone! It is also necessary to check refractive states such as myopia, hyperopia and astigmatism. And the corrected visual acuity was measured, This requires optometry in a regular hospital. For children, Mydriasis optometry is necessary, The aim is to relax the adjustment, Stabilize the refractive state, So as to perform accurate optometry. The commonly used drugs take effect quickly, The action lasts for 6-8 hours, It is normal to see nearly blurred and photophobia after eye drops. No other obvious side effects, It is very safe. After completion, the optometrist will issue an optometry report. It is useful to learn to read the optometry report. It can be compared before and after, Understand the refractive changes of children. The general optometry list is shown in the following figure: The spherical values in the table represent the degree of myopia or hyperopia, The medical unit is [D], 1 D = 100 degrees, [-] for myopia, [+] represents hyperopia. The spherical view of the right eye shows-1.50 D, That is, myopia is 150 degrees, Similarly, the above one is 175 degrees short-sighted in his left eye. The cylindrical lens value is [astigmatism] degree. The unit is also [D], and the axial direction represents the weakest refractive power of the eyeball in the direction of what. Corrected vision 1.0 means that after wearing such a pair of glasses with appropriate degrees, one can achieve vision of 1.0. Evaluating visual ability is not just a hero based on vision. It is very important to understand the refractive state of children. Remember to take children to have a light test.