Astigmatism: Astigmatism is the most common cause of poor vision in young children, about 82% of low vision in young children is caused by astigmatism; followed by farsightedness, myopia, strabismus and other congenital abnormalities. Therefore, kindergarten teachers and parents should be fully aware of the harmful effects of astigmatism on the vision of young children. Astigmatism is a congenital variation (born of the mother, it may be related to the asymmetric development of the eye caused by inhaling more artificial food, organic pesticides or harmful gases during pregnancy), which can be simply seen as a “black eye” that is not round but oval (like an egg), resulting in different refractive power in the horizontal and vertical directions of the eye, forming astigmatism. 100 degrees or more of astigmatism can cause amblyopia. Astigmatism of more than 100 degrees can cause amblyopia. 2, hyperopia or myopia, hyperopia over 300 degrees, myopia over 600 degrees can cause the occurrence of amblyopia. 3. Although strabismus and nystagmus are rare, the amblyopia caused by them is extremely serious and should be checked and treated at the hospital as soon as possible.