The distinguishing feature of red eyes is the redness of the eyes, which is a red with blood, not a patchy redness. If it is a patchy redness, it is not congestion, but bleeding. There are other uncomfortable symptoms, such as foreign body sensation, burning sensation, photophobia, tearing, and itchy eyes, which are some of the prominent features of pink eye. If the discharge is yellow and purulent, bacterial conjunctivitis is more likely; if the discharge is watery or the eyes are very red and swollen, viral conjunctivitis is more likely. If the eyes are very itchy and red and swollen, allergic conjunctivitis is more likely. Therefore, the clinical manifestations of different types of conjunctivitis are slightly different, but they all have in common the redness of the eyes, that is, the phenomenon of red blood, and all will have a small amount of discharge.