If the baby is premature, if the baby has a low birth weight, and if the baby has a history of oxygen inhalation, it is important to remember to perform fundus screening 4-6 weeks after his/her birth or when the corrected gestational age reaches 32 weeks. Giving preterm babies high levels of oxygen has greatly improved their survival rate, but with it comes blindness in some children. As the survival rate of preterm infants increases, this condition, known as retinopathy of prematurity (ROP), is gaining attention. The retina of preterm infants is not yet fully developed, with the periphery being the least mature. In a hyperoxic environment, retinal vascular constriction and obstruction cause local ischemia and hypoxia, inducing abnormal retinal vascular proliferation, which leads to a series of changes such as exudation, hemorrhage, and mechanization. The abnormally proliferated retinal blood vessels develop through the inner boundary membrane to the retinal surface and extend into the vitreous, and as a result of vascular mechanization within the exuded vitreous, connective tissue membranes are formed behind the crystal, and retinal detachment can also be formed by pulling. Once ROP occurs, the disease progresses rapidly. Early lesions can be closely observed, and some children’s lesions can subside on their own. Laser and cryotherapy are available for progressive lesions, and most of the lesions can subside. However, advanced lesions can only be treated with vitreoretinal surgery, which is very ineffective. The prevention of retinopathy of prematurity is mainly from two aspects: First, reasonable oxygen therapy and care is the key to prevention. The Chinese Medical Association has formulated the “Guidelines for the Treatment of Premature Infants with Oxygen and Prevention of Retinopathy”, which should be strictly followed by medical personnel in the course of practice. With the development of medical science and medical technology, the survival rate of premature and low weight newborns has been increasing, and many premature and low weight newborns that were difficult to survive under the original medical conditions have survived. If we do not strictly grasp the indications and specifications for the use of oxygen therapy, innocent babies will have to pay a heavy price for this. Second, within the treatable “window of time” for fundus screening, and follow-up observation. All preterm infants who have undergone oxygen therapy and meet the criteria for ophthalmic screening should undergo ophthalmic ROP screening at 4 to 6 weeks after birth or at 32 to 34 weeks of corrected gestational age for early detection and early treatment. Retinopathy of prematurity often appears 3 to 6 weeks after birth, and only if detected during this active period and necessary measures are taken, the child’s vision can be saved. Once the time window for treatment is missed, the child also misses the opportunity to have light forever. We often encounter parents in the clinic who bring their 5- or 6-month-old children for retinal screening of prematurity, and these parents of preterm babies often know little about the condition. If the child does unfortunately develop this pathology, it is already too late at 5 or 6 months of age. Therefore, when using oxygen in preterm infants, especially in very low weight infants, the medical staff should inform the parents about the immaturity of the blood vessels of preterm infants, the necessity of using oxygen in preterm infants and the possible dangers. In conclusion, blindness caused by retinopathy of prematurity is completely preventable, so don’t ruin your child’s light because of ignorance.