It is generally thought, though unclear at present, that the disease is caused by polygene or multiple factors. From its clinic manifestations, the disease should pertain to"Qingfeng Neizhang"(bluish glaucoma) in traditional Chinese medicine.  Its occurrence is much concerned with the factors of qi stagnation, phlegm-fire, injury from overstrain, yin deficiency and so on.  The main pathogensis of the case is due to the fact that the invasion of eye by pathogenic factor causes the circulation disorder of qj and blood and obstruction in vessel and meridian so that accumulation of the aqueous humor arises. And those who often show wind syndrome of head, phlegm-fire and deficiency of yin and blood may easily develop the disease.

According to the theory of traditional Chinese medicine, there are some patterns of syndrome that lead to primary open-angle glaucoma.
1. Syndrome of Pathogenic Fire due to Qi Stagnation
2. Syndrome of Ocular Invasion of Phlegm-fire
3. Syndrome of Wind Stirring due to Yin Deficiency