Drinking tea is said to be beneficial for the eyes, a claim often found in ancient Chinese medical texts on herbs. In the Ming Dynasty, Li Shizhen wrote in the Compendium of Materia Medica: “Tea has a bitter taste and a cold nature… it is most effective in reducing internal heat, which is the root of all diseases. When heat is reduced, the upper body becomes clear.” Ming Dynasty scholars Qian Chunnian and Gu Yuanqing, in their work Tea Manual, provided a comprehensive discussion on the functions of tea, affirming that tea can “brighten the eyes and enhance mental clarity.”
Tea leaves contain many nutrients, especially vitamins B1, B2, C, and A, all of which are indispensable for maintaining the physiological functions of the eyes. Vitamin A is a key component for the function of the retina; vitamin B1 is a nutrient that sustains the physiological functions of the optic nerve; vitamin B2 plays a role in cellular oxidation-reduction and nourishes the epithelial tissues of the eyes; and vitamin C is a nutrient for the lens, with insufficient intake being one of the factors leading to cataracts. Therefore, regular tea consumption is very beneficial for maintaining vision and eye health.
In addition to internal consumption, tea can also be used externally to treat eye diseases. For example: 25 grams of green tea boiled in water, clarified, and used as an eye wash can be effective for blepharitis (commonly known as red and inflamed eyelid margins) and acute contagious conjunctivitis (commonly known as pink eye).