I d like to know your son s age , because if he is a newborn , then we should worry about bacterial conjunctivitis which should be treated with topical antibiotics , and sometimes it is associated with blockage in nasolacrimal duct which is a small tube that drains the tears , and that needs massage , saline irrigation and antibiotics if your son is older than that , it s possible it may be a viral infection and that is highly contagious to other kids and adults especially if there is a red eye , runny nose and mild cough . in that case we can use local antibiotic because it s difficult to tell viral from bacterial based on clinical alone. I hope this helps