Subconjunctival hemorrhage, also known as red eye, is an ophthalmologic disease characterized by patchy light red bloody macules under the surface of the bulbar conjunctiva. In some cases, it may cover the entire sclera. It occurs when small vessels in the eye rupture. Causes include violent sneezing or coughing increases in blood pressure as well as in those taking blood-thinning medications.

In TCM, subconjunctival hemorrhage is referred to as bái jīng yì xuè (白睛溢血, blood spillage in the white of the eye). It usually results from heat invading the lung channel, which causes a failure of lung qi to descend, which forces, the blood to move frenetically and spill into the sclera. Alternately, it can be caused by yin deficiency and essence loss due to aging, causing deficient heat to rise and resulting in blood spillage and damage to the collaterals. Other causes include external injury damaging the eye collaterals causing blood spillage into the sclera, strong coughing, excessive consumption of alcohol and vicarious menstruation. The etiology of this condition relates to an imbalance among the lung, kidney, liver and other specifc organs, and will manifest with paterns of both excess and defciency.