An important principle in the diagnosis and treatment of amblyopia is “early detection and early treatment”. It directly affects the outcome of amblyopia treatment. The early detection of amblyopia is of great clinical importance. You can start from the following aspects: 1. 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 acuity teaching. Kindergartens that have the conditions should conduct an annual census screening of children’s vision, parents can also purchase a standard vision chart, hung on a well-lit wall, in 5 meters away for 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. 2, 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 eye examinations and confirm the diagnosis as soon as possible, because about 1/2 of strabismus combined with amblyopia. Other abnormalities mentioned above should also be taken seriously and noticed, and should be checked by the ophthalmology department of the hospital to see if they are caused by eye disorders. 3. In addition, for infants and children who cannot cooperate with the vision check, a masking test can be done to get a general idea of the vision of both eyes. If the child is quiet and the other eye is crying or scratching the mask, the vision in the uncovered eye is very poor, so go to the hospital as soon as possible. In conclusion, early detection of amblyopia depends on the close cooperation of parents, kindergartens, schools, hospitals, and most importantly, the parents themselves who spend time with their children.