Examination to confirm the diagnosis of allergic conjunctivitis is based on three aspects: first, the main manifestations of allergic conjunctivitis are redness of the eyes, conjunctival vasodilatation, itching of the eyes, and a large amount of viscous, pulpy, transparent secretions in the conjunctival sac, which may be accompanied by tearing and photophobia. Secondly, the main manifestation of physical signs is slit-lamp microscopic examination found that the conjunctiva appeared edema, lid conjunctiva with follicle and papilla formation, some patients have gelatinous bulge at the junction of black and white eyeballs. Third, laboratory examination is currently the diagnosis of allergic conjunctivitis, the most accurate way, mainly relying on conjunctival impression cytology, by observing the proportion of eosinophils in the leukocytes shed in the conjunctival capsule, if there is an elevated eosinophil count, it can be diagnosed as allergic conjunctivitis, diagnosis of allergic conjunctivitis through the above three aspects of the examination.