The symptoms of conjunctivitis vary according to the cause, individual variability, and severity of the disease. Depending on the condition and course of conjunctivitis, it can be divided into acute, subacute and chronic; according to the etiology, it can be divided into bacterial, viral, chlamydial, fungal and allergic; according to the characteristics of conjunctival lesions, it can be divided into acute follicular conjunctivitis, chronic follicular conjunctivitis, membranous and pseudomembranous conjunctivitis, etc. Symptoms of conjunctivitis commonly include red eyes, itchy eyes, foreign body sensation, burning sensation, heavy eyelids, increased secretions, photophobia, tearing and varying degrees of vision loss when the lesion involves the cornea, and possibly edema of the eyelids. These symptoms do not all occur and are not uniform in degree. For example, bacterial conjunctivitis has a yellowish-white pus-like discharge, viral conjunctivitis has a watery discharge, and allergic conjunctivitis has more intense eye itching with severe conjunctival edema. Generally, the symptoms of acute onset conjunctivitis are more severe than chronic ones. Thus, the symptoms of conjunctivitis are diverse and vary according to the cause, individual variability, and severity of the condition.