It's cause and pathogenesis, though unclear at present, is believed to be probably connected with the factors of heredity, nutritional imbalance, chronic light injury, poisoning, immune diseases and so on, or may be the result of the complicated action of multiple factors. From the clinical manifestations, the disease should pertain to "Shizhan Hunmiao" (blurring of vision) in traditional
Chinese medicine. Its occurrence is associated with the irregulation among the organs of the liver, spleen, stomach and kidney, and it often arises as a result of deficiency of the liver and kidney, asthenia of primordial essence, or is caused by the incoordination between the liver and spleen and obstruction or stagnation of meridian and vessels.