The eye surface is directly exposed to the external environment and can come into direct contact with allergic substances, making it prone to various allergic diseases. Common allergic diseases of the eye are divided into five main types: 1, allergic conjunctivitis: the most common, accounting for about 50% of allergic diseases of the eye; 2, spring cataract keratoconjunctivitis: mostly seen in adolescents, often occurring or aggravated in spring and summer, the ratio of male to female disease 2:1, the incidence of hot flashes in the region is higher, serious patients can affect vision. 3, giant papillary conjunctivitis: associated with wearing corneal contact lenses, prosthetic eyes, exposed sutures, 15% of patients wearing soft corneal contact lenses can occur giant papillary conjunctivitis; 4, atopic keratoconjunctivitis: is a kind of keratoconjunctivitis associated with atopic dermatitis, congenital allergy is the main factor, the peak age of onset is mostly in the 30 to 50 years old. 5, contact allergic conjunctivitis: patients often have a clear history of exposure, such as a history of exposure to drugs, cosmetics or hair dyes, and avoidance of contact relieves symptoms.