Painful, itchy, red bloodshot eyes are mostly caused by conjunctivitis. If the eyes are obviously congested with blood, and there is an increase in yellowish-white discharge, it is usually related to bacterial infection, causing conjunctivitis, and it is recommended to use antibiotic eye drops and antibiotic ointment for treatment. If the eye discharge is watery, it may be caused by a viral infection that causes conjunctivitis, which usually starts in one eye and then the opposite eye a few days later, and in some patients, there are also enlarged lymph nodes in front of the ear. After diagnosis, treatment with antiviral eye drops and ointment is recommended. Pain, wheezing, and congestion can also develop when implanted eyelashes, or conjunctival stones protrude from the conjunctival surface of the lid. If the itching of the eyes is prominent, or even unbearable, accompanied by wheezing, pain, blood and edema, it is considered to be caused by allergies.