External obstruction

Any disease of the eyelids, canthi, white of the eye or dark of the eye. External obstructions include red sore swollen eyes (e.g., wind-fire eye), erosion, tearing, eye discharge, or dryness of the eyes, eye screens and membranes, and excrescences of the canthi. They may be attended by subjective sensations such as pain, itching, dryness, and aversion to light. They are mostly attributable to invasion of the six excesses or depressed heat or phlegm-fire in the inner body, or to external injury. In some cases, they may be attributable to liver-kidney vacuity with vacuity fire flaming upward or spleen qì vacuity. Compare internal obstruction.