It depends on the severity of the jaundice, the duration of the blue light exposure and the baby’s reaction to the blue light, so it is important to analyze the specific problem. Babies with pathological jaundice need to be exposed to blue light for at least 5-7 days, 6-8 hours a day, as this method has few side effects and regresses the yellowing more quickly. The bilirubin level in the blood should be monitored when blue light is administered. If the baby has mild pathological jaundice, blue light exposure is usually required for 3-4 days. If the jaundice is moderate, the baby will usually need to be exposed to blue light for 5-7 days. If the jaundice is severe, treatment should be continued for more than 1 week, with each blue light exposure lasting for about 12-16 hours. During blue light treatment, care should be taken to avoid exposing the baby’s eyes and perineum to blue light, and protective measures such as wearing eye shields and diapers can be taken.