The conjunctiva is a soft, smooth and transparent film located on the inner surface of the eyelid and the surface of the eye. Conjunctivitis is usually effectively treated topically (i.e., by applying eye drops or ointment) without the need for medication, and the concentration of oral medication reaching the eye through the bloodstream is very low and not as effective as topical application of eye medication. Unless the conjunctivitis is caused by systemic infection or allergy, systemic treatment with antibiotics or anti-allergy medications is required. The first step in conjunctivitis is to identify the cause of the disease and what is causing the conjunctivitis. The causes of conjunctivitis can be divided into two categories, infectious and non-infectious, depending on their different nature. 1. Infectious: inflammation of the conjunctiva due to infection by pathogenic microorganisms. 2. Non-infectious: allergic inflammation caused by local or systemic allergic reactions is the most common. External physical and chemical factors such as light and various chemicals can also be causative factors. In case of infectious conjunctivitis: treat with the following methods: 1, flush the conjunctival sac, using saline can be used, its role is mainly to clean, do not cover the affected eye. 2. Topical antibacterial or antiviral eye drops or eye ointment. According to the pathogenic diagnosis, choose the appropriate therapeutic drugs. 3. Systemic treatment For severe conjunctivitis, a combination of systemic medication, such as oral antibiotics, is required. In case of non-infectious conjunctivitis, such as allergic conjunctivitis, do not abuse antibiotics, but use anti-allergic eye drops, such as sodium cromoglycate eye solution, and oral anti-allergy medication in severe cases.