A six-year-old child’s vision should normally be about 0.8, which is the normal vision. If the child’s vision is not in this range, such as significantly lower than normal, this indicates the existence of eye disease, after the emergence of this situation, to go to the hospital as soon as possible for a detailed examination, to understand the specific causes of vision loss, so as to know how to treat. The first is refractive error, such as myopia, hyperopia or astigmatism, which must be clarified by an optometric examination and, if necessary, glasses to improve vision; the second disease is amblyopia, which is also a very common eye disease in children, refers to the critical period of vision development, due to the presence of some adverse factors, such as high The second disease is amblyopia, which is also a very common eye disease in children. It is a condition in which the vision is not fully developed due to the presence of adverse factors, such as high farsightedness, high astigmatism, refractive error or congenital cataract or corneal clouding.