It is said that the description of an ocular disorder related to the color of the sea in the Hippocratic Corpus is the oldest medical reference to glaucoma. In the early Edo period in Japan, the Books of Secrets of the Majima school, describe a disorder called ao-sokohi. This nomenclature is believed to be based upon the Five Elements' Theory (Wu-Xing Thought)in ancient China, which assigned five colors for intraocular disorders ("naisho/sokohi" in Japanese),blue ("ao" in Japanese), red, yellow, white and black. In Japanese literature, in late Edo period, "ryoku-naisho (glaucoma)" appeared after the publication of Dutch-Japanese translation by Dutch scholars. The Japanese name is thought to derive from "Glaukos" which means green in ancient Greek. Since the Meiji period, "ryoku-naisho (glaucoma)" has been used in most textbooks including those by foreign teachers and the works of Jujiro Komoto, the first Professor at the Department of Ophthalmology of (Tokyo) Imperial University.
Nippon Ganka Gakkai Zasshi (J Jpn Ophthalmol Soc) 120: 369-381, 2016.