Coats disease, also known as outer exudative retinopathy, is a congenital disease, but is not inherited. It has two characteristics: first, it is particularly likely to occur in boys over 5 years of age, and second, more than 90% of the cases are in one eye, although there are exceptions. If the affected eye is not treated in time, it can also cause blindness and even eye atrophy, so it should attract the attention of parents and doctors. Early diagnosis and standardized treatment of the disease is the key to saving vision and the eye.