The conjunctiva is the name of a structure in the eye. The conjunctiva is a soft, smooth and transparent membrane located on the inner surface of the eyelid and the surface of the eye. The conjunctiva is rich in blood vessels and nerve endings and contains a small number of mucus glands that secrete mucus and moisten the eye. In normal living bodies, the conjunctiva is red and moist, through which the capillaries on its deeper surface can be observed; in varying degrees of anemia, the conjunctiva becomes lighter or paler; in inflammation, the conjunctiva becomes congested, called conjunctivitis, which is commonly known as “red eye” and is a common clinical disease. According to 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, and photophobia, tearing and varying degrees of vision loss when the lesion involves the cornea. The conjunctiva has a barrier effect and is in contact with the outside world, so it is also more susceptible to inflammation from external bacteria, viruses or physical stimuli.