Chinese woodcut: Eye diagnosis -- the five spheres (wu lun)

Unknown artist

Lettering: PICTURE TITLE: Five spheres (wu lun). OTHER LETTERING: Neizi (inner canthus of the eye); spleen; ruizi (acute canthus, i.e. outer canthus of the eye); heart; liver; lung; stomach. Ruizi (acute canthus) or xiaozi (small canthus), relates to the heart and the small intestine. The pupil relates to the kidney, it is termed shui lun (water sphere). Heizhu (the cornea) relates to the liver, it is termed feng lun (wind sphere). Baizhu (the white of the eye) relates to the lung, it is termed qi lun (Qi sphere). Dazi (the large canthus, i.e. inner cathus of the eye) relates to the heart, it is termed xue lun (blood sphere).