Does a decrease in vision mean myopia? "" If a child's axial length increases, does myopia also increase? "" As long as they wear myopia glasses, the degree will get higher and higher. "During holidays, ophthalmology departments in various hospitals in Shanghai will see a peak in visits. Many parents consult doctors with their children with poor vision about various vision health issues. As more and more families pay attention to visual health, some erroneous views on myopia prevention and control are also spreading. Regarding this, Qiao Tong, the director of the ophthalmology department at Shanghai Children's Hospital, clarified one by one the common problems encountered during outpatient visits. Misconception 1: Decreased vision refers to nearsightedness. Many parents believe that their children are nearsighted when they notice symptoms such as "not being able to see clearly in the distance" or "squinting their eyes to see things". But in the eyes of ophthalmologists, 'vision loss' is just a vague concept. Children's vision decline may be caused by refractive errors, but there are also other reasons, such as partial traumatic brain injury, systemic diseases, etc., which can lead to vision decline. Qiao Tong reminds that "refractive error" does not necessarily mean myopia. Because refractive errors include three types: myopia, hyperopia, and astigmatism. To understand the specific reasons for the decline in a child's vision, it is necessary to go to a regular hospital for a scientific refractive examination to determine the child's specific refractive condition, and then receive treatment based on the refractive condition. Misconception 2: An increase in axial length indicates a worsening of myopia. More and more parents are becoming aware of the term 'axial length' and are anxious when they see their children's axial length increase, even if their refractive power does not increase. This is because some institutions currently claim that 'axial length is the only standard for measuring changes in myopia', which is actually a biased understanding. ”Qiao Tong said that the relationship between axial length and myopia degree is a common question encountered in outpatient clinics, and some parents are even emotionally excited about their children's axial length growth. In fact, the refractive power obtained through dilated pupil refraction is the most accurate indicator for evaluating the degree of myopia in children, while the axial length can only be used as an auxiliary indicator. This is because the "eye axis" measured by various hospitals and ophthalmic institutions cannot accurately reproduce the length of a child's eye axis. At present, the eye axis measured clinically is the distance from the corneal tip to the retina measured by optical equipment. Specifically, the eyeball is like a sphere, and current measurement methods mainly focus on its anterior posterior length, with less emphasis on measuring the horizontal width of the eyeball. During the growth and development period of a child, if the eyeball is "uniformly enlarged" (the anterior posterior diameter and horizontal diameter grow synchronously), the refractive status may remain unchanged. In this case, axial growth is a normal physiological development and does not represent a deepening of myopia. In addition, the causes of myopia are complex. If high myopia is caused by excessive corneal curvature (curvature myopia), even if the degree is high, the axial length of the eye may still be within the normal range. Moreover, due to physiological factors such as intraocular pressure and body position, there may be slight fluctuations in the eye axis within 24 hours. All of the above indicates that the eye axis can only be used as one indicator for comprehensive evaluation, rather than the sole criterion. Parents should not be overly anxious when they see their children's axial length increase. Instead, they should combine the results of a formal refractive index test and listen to the professional analysis of a doctor. Misconception 3: After wearing glasses, the degree will increase. When a child has refractive errors, many parents have doubts about whether to wear glasses, and some even refuse to let their child wear glasses because they are worried that the degree will increase after wearing glasses. Qiao Tong joked that this is the "black pot" that glasses have been carrying for a century. The function of glasses is to correct refractive errors and help people with vision problems see more clearly, without affecting their life, study, and work due to refractive errors; It's not just after wearing glasses that myopia worsens. This is equivalent to traveling to Antarctica and discovering that it is very cold. We will inevitably wear down jackets to keep warm, so that we can operate in Antarctica. But obviously it's not because of wearing down jackets that Antarctica will become colder. ”Qiao Tong often uses this analogy to explain the function of glasses to parents during consultations. Similarly, it is necessary to clarify the viewpoint that 'wearing glasses can cure refractive errors'. Qiao Tong said that similar to the saying "down jackets only help us adapt to the cold environment in Antarctica, but cannot help the body generate heat itself", glasses can help some people compensate for refractive errors, but cannot make the defects disappear. Because of this, there are many devices and products on the market that claim to be able to "cure" or "reverse" refractive errors, but in fact, they are changing concepts and deceiving consumers. Some of them may affect the degree of refractive errors in a short period of time, giving people the illusion that their vision has improved; In fact, they cannot fundamentally change refractive errors, neither can they "reverse" myopia, nor can they "cure" myopia. Misconception 4: Myopia will not deepen in adulthood. During growth and development, a child's refractive power may undergo certain changes. Generally speaking, after the age of 18, a person's vision will be relatively stable. Because of this, the vast majority of laser correction surgeries for refractive errors are performed after the age of 18. Moreover, whether laser correction can be performed requires a comprehensive evaluation by a reputable hospital. But Qiao Tong reminds that with changes in lifestyle habits, including long-term use of electronic devices, staying up late, and increased work pressure, some adults' myopia may continue to increase, even in their thirties and forties, myopia may worsen. In addition, some diseases can also affect vision. So, if there is a sharp decline in vision in adulthood, including sudden abnormal changes in myopia degree, it is necessary to go to a regular ophthalmic institution for examination, find the cause of vision decline, and prescribe the right medicine. At the same time, in order to reduce the impact of electronic screens on vision, even adults should pay attention to eye hygiene. The simplest rule is to remember the "3 20s": every 20 minutes of eye contact, gaze at a distance of 20 feet (about 6 meters) for at least 20 seconds. In short, paying attention to eye hygiene and protecting vision should become a lifelong habit. (New Society)