The baby is one month old and his eyes are a bit yellow, which may be caused by jaundice, mostly seen as breast milk jaundice or pathological jaundice. 1. Breastfeeding jaundice: it usually occurs in babies who are exclusively breastfed or breastfed, the specific cause is still unclear, it may be related to the enzymes or genes in breastmilk, it usually occurs about 1 week after birth, and then gradually subsides, there are some breastfeeding jaundice, which lasts for a longer period of time. 2. Pathological jaundice: mainly caused by abnormally high bilirubin level, mostly seen in hemolytic disease, congenital biliary atresia, etc. It may lead to yellow staining of the skin sclera or other organs, that’s why the eyes feel a little yellow. The baby is a month old, eyes a little yellow, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.