The first step in conjunctivitis is to identify the cause of the disease and what is causing the conjunctivitis. The etiology of conjunctivitis can be divided into two categories, infectious and non-infectious, depending on its different nature. (i) Infectious due to infection of the conjunctiva by pathogenic microorganisms. Non-infectious allergic inflammation caused by local or systemic allergic reactions is the most common, and external physical and chemical factors such as light and various chemicals can also be causative factors. Conjunctivitis in children is also mostly caused by these two etiologies due to lack of hygiene, greed for playing with dirty hands and rubbing eyes, and the fact that conjunctival tissue is not fully developed and susceptible to allergenic substances. In case of infectious conjunctivitis: antibacterial or antiviral eye drops or eye ointment. Depending on the etiologic diagnosis, choose the appropriate therapeutic medication. For example, tobramycin eye solution and erythromycin eye ointment are available for bacterial infections, and acyclovir eye solution is available for viral infections. For non-infectious conjunctivitis, such as allergic conjunctivitis, do not abuse antibiotics, but use anti-allergy eye drops, such as sodium cromoglycate ophthalmic solution. Therefore, children with conjunctivitis should be treated according to the specific cause and avoid drugs that are not suitable for children.