White membranous material on the eyeball is usually caused by conjunctival edema, blepharospasm and conjunctival lymphocysts. 1. Conjunctival edema: mechanical stimulation caused by rubbing the eyes or allergies may cause a large amount of fluid to pool in the conjunctival tissue interstitial space, resulting in the formation of edema, which is manifested as a white membrane. 2. Blepharospasm: abnormal proliferation of conjunctival tissue on the surface of the white eyeball, resulting in the formation of a white membranous structure, commonly found in middle-aged and elderly people as well as laborers who are exposed to strong sunlight for a long time. 3. Conjunctival lymphocysts: small cysts formed by the stagnation of lymphatic fluid due to the blockage of lymphatic vessels in the conjunctival tissues, usually appearing in clusters, which looks like a layer of mucous membrane-like tissue on the surface of the white eyeball. Patients who have white membranous material on the eyeball, please go to the hospital in time, after clarifying the cause of the disease, and actively cooperate with the doctor to carry out targeted treatment.