With the development of medical treatment, premature babies are becoming more and more common. Parents of premature babies must pay attention and take their premature babies to the ophthalmology department for fundus check before the full moon. I. Why do preterm babies need to have their fundus checked? Premature infants are born with immature blood vessels in the fundus (retina), and are prone to abnormal retinal vascular development, hemorrhage, retinal detachment and eventual blindness under the influence of various factors after birth. This means that premature infants are prone to retinopathy of prematurity (incidence about 10%), and retinopathy of prematurity is one of the main causes of childhood blindness. If detected early and treated promptly, the affected children can maintain good vision. Once the treatment window is missed, retinal detachment occurs. Even if surgery is performed, the result is poor and the child is likely to be completely blind. Second, which premature babies need fundus check? According to the guidelines for the prevention and treatment of retinopathy of prematurity in China, preterm infants with birth weight <= 2000g or gestational weeks <= 32 weeks need to undergo fundus screening. The weaker the preterm infant, the more likely he or she is to develop retinopathy of prematurity. When should I go for screening? Premature infants need to be screened 3-4 weeks after birth because some of them have already developed more serious retinopathy of prematurity that needs to be treated 3-4 weeks after birth, and if they are late, they are likely to miss the treatment time. Some parents do not go to the hospital for screening because their children are weak or because they think they are still too young because they are not full term. Missing the best time for treatment will leave lifelong regrets. Fourth, how to check the fundus of preterm infants? Fundus screening for preterm infants needs to be performed by an experienced fundus physician under an indirect ophthalmoscope combined with scleral compression. Some children need further pediatric color fundus photography. One hour before the examination, you need to order dilating eye drops and do not drink milk one hour before the examination to avoid crying and choking during the examination.