An anxious mother said that her daughter was 2 years old and she had noticed by chance that the pupil area of her right eye was white and she could not see. She wanted the doctor to examine her right eye to see if it could be saved. The doctor took a medical history and found that the girl was born prematurely, weighing only 1.2 kg at birth, and had a history of multiple episodes of oxygen intake. After examination, her daughter was diagnosed with retinopathy of prematurity in her right eye. The mother was devastated and regretted that it was found too late and regretted not bringing her child to the hospital earlier. What kind of disease is retinopathy of prematurity and how dangerous is it? Retinopathy of prematurity, or ROP for short, is a proliferative retinopathy that occurs in infants born prematurely or at a low birth weight, ranging from minor changes in the peripheral fundus to complete loss of visual function. The prevalence of ROP in preterm infants ranges from 15% to 30%, and the shorter the gestation period and the lower the birth weight, the higher the prevalence. The prevalence rate is 40% for those with an average birth weight of 1000 grams and up to 70%-80% for those below 1000 grams. In the past, the mortality rate of preterm infants was high, and the introduction of high oxygen concentration in the care of preterm infants from the 1940s led to a significant increase in the survival rate of preterm infants. However, this was followed by the development of retinopathy of prematurity in low birth weight preterm infants who had received high concentrations of oxygen. It has been shown that prematurity, low birth weight, and severe systemic disorders are risk factors for retinopathy of prematurity. ROP is now the leading cause of childhood blindness worldwide. Therefore, the key to preventing ROP in preterm infants is to control the systemic condition of preterm infants, low birth weight infants, and children with severe systemic diseases, and to control the duration and concentration of oxygen when using oxygen. In addition, it is most important to have regular fundus examinations. It is generally emphasized that the fundus should be checked 4-6 weeks after birth. Once a lesion is found, it should be closely followed up; when it reaches the threshold lesion, immediate surgical treatment, either frozen or laser treatment, should be performed; if the lesion progresses to retinal detachment, scleral buckling and vitreous surgery should be considered. If every parent understands this disease and actively cooperates with the ophthalmologist in the examination and treatment, they can prevent their children from having unfortunate encounters like the one of the little girl in front of them. In conclusion, the disease requires the joint efforts of pediatricians, obstetricians, ophthalmologists and parents for early detection, early diagnosis and early treatment to prevent retinopathy of prematurity from causing blindness.