Red eyes are usually a manifestation of conjunctival congestion, which can occur in many diseases, the more common ones are as follows: first, local inflammation caused by bacterial infection, such as bacterial conjunctivitis or bacterial keratitis, which needs to be treated with antibiotic drugs, such as levofloxacin hydrochloride eye drops; second, uveitis or sclerositis, which, in addition to eye congestion, can also present with eye This disease is caused by abnormal local immune mechanism, and needs to be treated with glucocorticoids and ciliary muscle paralyzing agents, such as compound tropicamide eye drops, atropine eye drops, and flomiron eye drops; thirdly, glaucoma, which generally manifests as swelling and pain in one eye, vision loss, and conjunctival congestion, and needs to be treated by lowering eye pressure.