Red and swollen eyes in infants may be caused by allergy, inflammation, environmental factors and other reasons. 1. Allergy: allergic conjunctivitis caused by infants’ contact with allergens can lead to symptoms such as red and swollen eyes due to the body’s immune response. 2. Inflammation within the eye: it may be caused by blepharitis, conjunctivitis, etc. Due to the stimulation of inflammation, the eyes of the child may appear red, swollen, painful and other symptoms. 3. Environmental factors: windy, dusty and smoky living environment can stimulate the eyes, causing eye foreign body sensation, infection and other phenomena, resulting in redness and swelling of the eyes. Red and swollen eyes in infants can also be seen in other diseases, it is recommended that patients go to the hospital in a timely manner, in accordance with the doctor’s instructions for treatment, to avoid delaying the condition.