The redness of the eyes of 20-month-old babies is mostly related to the occurrence of acute or subacute bacterial conjunctivitis, and may also be caused by trachoma or seasonal allergic conjunctivitis and other diseases. 1. Acute or subacute bacterial conjunctivitis: children are mostly infected with germs in the spring and fall seasons causing acute or subacute bacterial conjunctivitis, commonly known as red eye, such as children occurring pneumococcal conjunctivitis, there can be conjunctival congestion, mucopurulent secretions, etc., the fornix conjunctiva and the conjunctiva of the upper eyelid will have subconjunctival hemorrhage as well as bulboconjunctival congestion. 2. Trachoma: when the eye is infected with Chlamydia trachomatis, there can be different degrees of clinical manifestations. When acute trachoma occurs, the eyes are photophobic, tearing, there are more secretions, and there can be eyelid redness and swelling, conjunctival congestion and so on. 3. Seasonal allergic conjunctivitis: often associated with pollen sensitivity, there are seasonal episodes, manifested as conjunctival congestion, lid conjunctival papillary hyperplasia, can be combined with eyelid edema and conjunctival edema. When the baby’s eyes are red, it is recommended to go to the hospital in time and follow the doctor’s instructions for treatment.