Eye redness in one eye is usually seen in the following two conditions: first, local inflammation, such as mydriasis, conjunctivitis, keratitis, uveitis, and sclerenitis. For this type of disease, it is recommended that the first thing to do is to go to the hospital for examination and clarification, and the treatment plan is different for different diseases. If the inflammation is caused by bacterial infection, anti-infective symptomatic treatment is usually required, and sensitive antibiotic drops and ointment are chosen to control the local inflammation; in the case of uveitis, which is usually caused by immune factors, topical ciliary muscle paralyzing agents and glucocorticoid drops are recommended; in the case of sclerositis, no treatment is usually required, but glucocorticoid drops can be used locally for a short period of time if the symptoms are severe. Corticosteroid drops can be used locally for a short period of time if the symptoms are more severe. Secondly, glaucoma is a manifestation of conjunctival congestion caused by elevated intraocular pressure. In this case, it is recommended to go to the hospital as early as possible for examination and diagnosis, and to give symptomatic treatment to lower the intraocular pressure to prevent irreversible damage to the optic nerve caused by high intraocular pressure.