Researchers report that flavonoids in green tea may offer protection against vision problems like cataracts, age-related macular degeneration, and some forms of glaucoma. One of the first senses affected by aging is eyesight.
Particularly the flavonoid called gallocatechin accumulates in the retina where it acts like a sunscreen protecting cells from damaging solar rays. Eating vegetables like kale, spinach and orange peppers protects eyes the same way.
Because of its high concentration of catechins, disease-fighting antioxidants, green tea has had the reputation for other health benefits like fighting heart disease and cancer. Other antioxidants reported to keep eye tissues healthy are vitamins C and E, lutein, and zeaxanthin. Until later studies it was not known if green tea catechins could be absorbed into eye tissue.
Lab results from researcher Kai On Chu, The Chinese University of Hong Kong's Department of Ophthalmology and Visual Sciences, and colleagues proved catechins do make it into eye tissue from the stomach and gastrointestinal tract with different parts of the eye absorbing various amounts of catechins. The highest concentration was in the retinas, the light-sensing tissues in back of the eyes; the least absorbing was the corneal outer eye layer. This study was done with rats so further study will be done on humans.
The required dose is small--one daily helping protects for about twenty hours. It should be easy for most Americans to drink one cup of green tea instead of coffee each day. It is a simpler way to get antioxidants anywhere rather than fresh fruits and vegetables, but those should be included in the diet as well.
Other suggested ways to protect the eyes in addition to drinking green tea and eating a diet rich in minerals and vitamins A and C are drinking bilberry juice which tastes similar to blueberry juice, taking bilberry pills, or taking krill oil in the form of astaxanthin pills. Astaxanthin is a powerful antioxidant and anti-inflammatory also used to treat inflammation, minor injuries and muscle strains.