Traditional Chinese medicine discusses the physiological functions and pathological states of the eye in terms of the doctrines of yin-yang and the live phases. According to these doctrines, the functions and disesases of the eye are intimately related to the strength of the internal organs (zang fu). Consequently, treatments given in ancient literature are mostly directed at the internal organs, especially (he liver. However, it is noteworthy that literature mentions many external factors that can directly affect the health of eyes without exerting their influence through the organs, and suggests numerous medicinal preparations to be applied to the eye directly. Despite this, nowhere in traditional literature is any attempt made to explain external factors influencing the eyes directly and topical preparations in terms of the yin-yang and five-phase systems of correspondence.