Amblyopia is a common and frequent disease in children and is one of the major eye diseases affecting children’s visual development. The prevalence rate among preschool and school-age children is about 3%, and there are more than 300 million children in China, with about 10 million amblyopic children. It has caused great concern among parents and ophthalmologists. The biggest danger of amblyopia is that children with amblyopia not only have low vision in both eyes or one eye, but also often do not have perfect binocular vision and cannot form stereoscopic vision, so children will not be able to engage in work that requires fine vision, which will directly affect future employment and bring great inconvenience to life, and in more serious cases, can lead to lifelong low vision and cannot achieve normal vision even with glasses. In addition, amblyopia often causes strabismus, which affects appearance and physical and mental health, and children with amblyopia often have low self-esteem and autism. So what is amblyopia? Due to the different focus of the description, the expression varies slightly. 1. The National Strabismic Amblyopia Prevention and Treatment Group of the Chinese Medical Association Ophthalmology Society (1987); where there is no organic lesion in the eye, functional factors are the main cause, and the distance visual acuity is less than 0.9, and the wearer cannot be corrected as amblyopia. 2, American textbook: amblyopia is no no organic pathology of the eye, with glasses can not correct the low vision, the most common cause is strabismus and refractive aberration. 3.American Academy of Ophthalmology Basic and Clinical Course in Strabismus and Pediatric Ophthalmology: Best-corrected vision loss in one or both eyes that cannot be directly attributed to any structural abnormality of the eye or visual pathway is caused by abnormal visual experiences early in life, often occurring from eye position deviation, uncorrected refractive errors and various diseases that cause a decrease in the quality of visual images. 4. National Strabismus Amblyopia Prevention and Treatment Group of the Chinese Medical Association Ophthalmology Society (2010); Best-corrected visual acuity in one or both eyes is lower than the age-appropriate visual acuity, or the visual acuity of both eyes differs by more than 2 lines during visual development due to monocular strabismus, uncorrected refractive aberrations and high refractive errors, and form deprivation. The development of vision in children is not from abnormal to normal, but from low norm to normal. Visual acuity varies at different ages. Generally speaking, 2-3 months visual acuity: 0.01-0.02 ,4-5 months visual acuity: 0.02-0.05 ,6-8 months: 0.06-0.1 ,9-12 months: 0.1-0.15 ,1 year: 0.2-0.25 ,2 years: 0.5 ,3 years: 0.7 ,4 years: 0.8 ,5 years and above: 1.0 . Treatment of amblyopia: With reasonable prescriptions and individualized treatment, the majority of children can improve their visual acuity and obtain normal vision, taking into account the developmental factors of children. Because of the early onset of amblyopia, the treatment effect is limited by age, the younger the age the better the effect, the older the treatment effect will be worse, in the plastic stage of visual development, should be detected early, early treatment, if amblyopia diagnosis is delayed, improper treatment or delayed treatment, will lead to lifelong low vision. How can we detect amblyopia in time? If a 1-year-old baby still can’t gaze steadily and follow objects; a toddler often collides on objects when walking; likes to walk very close when watching TV, or squinting his small eyes, or tilting his head …… When you find that your child has these phenomena, you should be alert to the possibility of amblyopia. This is a common cause of amblyopia, especially internal obliquity, or what we commonly call “cross-eyed”. This is generally easy to detect, but parents should be reminded that because of the low bridge of the baby’s nose, in many cases it looks like “cross-eyed”, but in fact it is a false internal strabismus, only the position of both eyes is asymmetrical, and one eye is skewed inward is the real internal strabismus, and doctors will identify it through professional examination. Once you find that your baby has low vision or strabismus in your life, you should go to a specialist hospital in time for an examination; even if there is no abnormal vision, amblyopia cannot be completely ruled out because the requirements for visual function are relatively low in the early years of a young child’s life, and mild to moderate amblyopia often cannot be demonstrated. In many developed countries, early screening of young children’s visual acuity is conducted, with comprehensive examinations of visual acuity, eye position, refraction, as well as hearing and speech at the ages of 2 and 4, in order to detect the presence of high-risk factors for the development of amblyopia, and to closely follow up and examine children at risk. Kindergartens in some cities in China are also starting to screen children for vision and eye disease, which can be very helpful in the early detection of amblyopia. If routine eye examinations cannot be done before the age of 3, it is essential for parents to have a detailed eye examination at a specialist hospital when the child is around 3 years old.