Red areola surrounding the black wheel

Also called redness hugging the wheel. From Reflections on the Silver Sea (银海精微 yín hǎi jīng wēi). A condition characterized by reddening of the white of the eye in the area surrounding the dark of the eye (the black wheel) in which red blood threads (i.e., blood vessels) are dimly distinguishable and do not disappear if pressure is applied. It is observed in several eye diseases including green wind internal obstruction (glaucoma).

Biomedical correspondence: ciliary congestion.