Consider allergic conjunctivitis, allergic conjunctivitis is due to contact with allergic antigen caused by conjunctival allergic reaction, the first step is to determine the allergens, and immediately remove the allergens, allergic conjunctivitis is not always able to find out the exact allergens, or allergens are complex, it is difficult to find out, which is the allergic conjunctivitis recurrence, not easy to cure the root cause.