I. What is amblyopia? Amblyopia refers to eyes without obvious organic pathology, but corrected visual acuity is less than 0.9. Currently, the standard for amblyopia in China is corrected visual acuity ≤ 0.8 or the difference in visual acuity between the two eyes ≥ 2 lines. Amblyopia is an eye disease that seriously endangers the visual function of children. If amblyopia in children is not detected and treated early, it will lead to low vision in one or both eyes, seriously affecting binocular vision and leading to fusion loss and stereo blindness. Amblyopia, however, is a curable disease if it occurs during the sensitive stage of visual development. How can parents detect amblyopia in their children at an early stage? Parents can detect amblyopia early by the following methods: (a) Preschool physical examination: In general, children, especially those who grew up in kindergartens, can recognize the visual acuity table at the age of 3 after simple visual recognition. Parents can also purchase a standard vision chart and hang it on a well-lit wall at a distance of 5m for their children to identify. If the vision of one eye is below 0.8, the child should be taken to the hospital for further examination. It is generally believed that it is best to check no later than 4 years old. (B) Early detection of the first signs of abnormalities. Children with amblyopia often have other manifestations besides low vision, such as strabismus, skewed head, squinting or close to the eyes, etc. Once a child is found to have strabismus, he or she should go to the hospital ophthalmology department as soon as possible for examination and diagnosis, because about 1/2 of strabismus combined with amblyopia. Other abnormalities mentioned above should also be taken seriously and checked by the hospital ophthalmology department to see if they are caused by eye disorders. (c) For infants and young children who cannot cooperate with the vision check, a masking test can be done to get a general idea of binocular vision: if one eye is intentionally covered and the child is allowed to see with one eye, and if the child is quiet and cries or tears the mask when the other eye is covered (irritation phenomenon), it indicates that the vision of the uncovered eye is very poor and should be checked at the hospital as soon as possible. Director Yu Gang reminds parents that early detection of amblyopia depends on the close cooperation of parents, kindergartens, schools and hospitals, and most importantly, parents themselves who spend time with their children. What are the causes of amblyopia? There are many causes of amblyopia, which are summarized as follows: pediatric strabismus, high hyperopia, myopia and astigmatism, congenital cataract, severe ptosis, and congenital optic center and optic nerve dysplasia. There are also many ways to classify amblyopia, and depending on the cause amblyopia can be divided into: strabismic amblyopia: patients with strabismus or had strabismus with amblyopia, but without fundus abnormalities. It is believed that this is because strabismus causes diplopia and visual disturbances that make the patient feel extremely uncomfortable, and the visual cortex of the brain actively inhibits the visual impulses transmitted from the macula of the strabismus, and the macular function of the eye is suppressed for a long time, resulting in amblyopia. This is the reason why Toto’s children suffer from amblyopia as we mentioned earlier. This kind of amblyopia is a consequence of strabismus, which is secondary and functional and therefore reversible, and the prognosis is good. Occasionally, however, a few primary cases do not improve significantly even with aggressive treatment. Refractive parallax amblyopia: Due to the unequal clarity of the images formed in the macula of the two eyes, even if the refractive error is corrected, the size of the images caused by refractive parallax is still unequal, which makes it difficult or impossible to fuse the images of both eyes into one, and the visual cortical center can only suppress the images of the eyes with refractive error, which results in amblyopia over time, which is also functional and therefore reversible. Formal deprivation amblyopia: In infancy, due to corneal clouding, congenital cataract, or ptosis blocking the pupil, the light stimulus cannot fully enter the eye, depriving the macula of the opportunity to receive normal light stimulation, resulting in functional impairment and amblyopia. Congenital amblyopia: The pathogenesis is not well understood, and Von Noorden speculates that newborns often have retinal or optic pathway hemorrhage, which may affect the normal development of visual function. Some congenital amblyopia is secondary to nystagmus. Refractive amblyopia: Mostly bilateral, it occurs in patients with high refractive error who have not worn corrective lenses and have equal or similar visual acuity in both eyes; refractive amblyopia is most often seen in people with hyperopic refractive error. This type of amblyopia has similar binocular vision and no binocular image fusion disorder, so it does not cause macular function inhibition, so after wearing suitable corrective glasses, vision can be gradually improved without special treatment, but it takes a long time. On the surface, the above five types of amblyopia are all amblyopia, but there are essential differences in the pathogenesis. Strabismus and refractive amblyopia have the same light stimulation into both eyes, and the macula of both eyes are involved in the development of visual function, so the prognosis is better. However, form-deprived amblyopia is a condition in which the visual function has not yet developed to a perfect or mature stage during infancy and childhood, and the retina does not receive enough light stimulation to fully participate in the development of visual function, resulting in amblyopia, which not only has low vision but also has a poor prognosis. The consequences of monocular disorders are more serious than those of binoculars. Therefore, special care should be taken when covering the eyes of infants and children due to eye disease to avoid the formation of deprivation amblyopia (especially in children under 6 months of age). The prognosis for congenital and form-deprived amblyopia is poor. Refractive error, strabismus and refractive amblyopia have a better prognosis. The key is early detection, timely and correct treatment, and most of the visual acuity can be improved and the possibility of obtaining normal vision is quite high. What is the difference between amblyopia and myopia? In clinical practice, many parents come to the doctor because they find that their children have poor vision and mistakenly believe that their children are myopic. In fact, amblyopia and myopia are not at all the same disease. Myopia tends to occur in school age and adolescents, is due to excessive tension in the eye adjustment muscle ciliary muscle or genetics and other reasons caused by the eye axis becomes long to see far unclear, see near clear eye disease, and the child wears glasses after correction of vision can be restored to normal; while amblyopia is mostly seen in preschool, myopic eyes, and amblyopia is a visual function development delay, disorder, often accompanied by strabismus, high refractive error, wear glasses vision can not be corrected to The eye disease is normal. The vision is not good at distance and near. The two diseases are fundamentally different. Amblyopia is much more harmful to children’s visual function than myopia. Because myopia is only to see far when vision loss, not accompanied by other visual function damage, vision correction is not limited by age; while amblyopic children not only low vision, can not be corrected, but also affect the development of binocular visual function, may not have binocular monocular function, no stereo vision, the future can not be competent driving, mapping and fine work, not only affect the future of work, but also directly affect the quality of our population. V. Can amblyopia be cured and at what age is the best treatment period? Factors that may affect the outcome of amblyopia treatment are: family history (amblyopia or/and strabismus), infantile disease, type of amblyopia, original visual acuity, refractive condition, type and degree of strabismus, age of first diagnosis and nature of gaze, etc. It has been clinically proven that the original visual acuity of the amblyopic eye (the milder the amblyopia, the higher the efficacy) and therefore whether amblyopia can be cured are related to many of these factors. Many parents think that amblyopia should be treated when the child is older, because the child will know better and the treatment will be easier to cooperate. This is because children’s visual function is unstable during their visual development, and they are prone to both amblyopia and normalization. Some studies have shown that the critical period is within 2 years old, the sensitive period is before 6-8 years old, the treatment effect is extremely poor after 10 years old, and it is almost hopeless to treat after 12 years old. The treatment of amblyopia is not an overnight matter, but a constant battle. Preschool children have more time to cooperate with the treatment, and some treatments after school will be affected by learning, which often makes the treatment difficult and affects the efficacy.