It is often believed that the disease, though the real cause is unknown, is a sort of immune trouble or an allergic conjunctivitis and pertains to allergic type I. The sensitinogens of the disease may be different plant pollens, microbial antigenic components, filthy dust, animal furfurs, feathers, changes of sunlight and temperature, and so on.

Clinical manifestations of the disease show that the case should pertain in traditional Chinese medicine to Shifuzheng (seasonal and periodical ophthalmopathy), Mu-yang (ocular itching) and Yangruo Chongxingzheng (in-sect-moving itching of eye). It is caused in most cases by the fact that the invasion of pathogenic wind repeatedly attacks between the lids and the connecting tissues, or that, when internal accumulated dampness of the spleen and stomach is frequently affected by pathogenic wind, the combatting pathogenic wind, dampness and heat all accumulates up to the eye and stagnates in the lid. It may arise as a result of deficiency of the liver and blood, for blood asthenia can raise endopathic wind which causes itching.