Woodcut from the Chinese medical text Yanke zhuan yao (Compiled Essentials of Ophthalmology), published in 1914 (3rd year of the Chinese Republic). It shows the names and relative positions of the eight regions (bakuo) of the eye. These comprise the sky or heaven (qian) region, the earth (kun) region, the wind (xun) region, the thunder (zhen) region, the water (kan) region, the fire (li) region, the mountain (gen) region, and the marsh or lake (dui) region. The white of the eye belongs to the heaven region, which corresponds to the lung and large intestine. The upper and lower eyelids belong to the earth, thunder and marsh or lake regions, which correspond to the spleen, the stomach, guanyuan (Pass to the Origin), the small intestine, the bladder and the sanjiao (Triple Burner). The two canthuses of the eyes belong to the fire region, which corresponds to the heart, the heart envelope (xinbao, pericardium) and mingmen (right kidney considered as Portal of Life). The cornea belongs to the wind region, which corresponds to the liver. The pupil belongs to the water region, which corresponds to the kidney. The mountain region corresponds to the gall bladder, which is in turn connected with the kidney.
