A daily cup of coffee can save your eyesight, scientists claim.
科学家称，每日一杯咖啡可以拯救你的视力。
A chemical found in the drink prevents deteriorating eyesight and possible blindness from retinal degeneration due to glaucoma（青光眼）, ageing and diabetes.
Researchers at Cornell Univesity in New York were looking at coffee's antioxidant effects when they made the discovery.
Coffee contains 1 percent caffeine but between 7 and 9 percent chlorogenic acid（绿原酸）which is a strong antioxidant.
The study, published in the Journal of Agricultural and Food Chemistry, found that in mice this acid prevented retinal degeneration.
Chang Y. Lee, a professor of food science and the study's senior author said: 'The retina is a thin tissue layer on the inside, back wall of the eye with millions of light-sensitive cells and other nerve cells that receive and organise visual information.
'It is also one of the most metabolically active tissues, demanding high levels of oxygen and making it prone to oxidative stress.
'The lack of oxygen and production of free radicals leads to tissue damage and loss of sight.'
He added: 'The study is important in understanding functional foods, that is, natural foods that provide beneficial health effects.
'Coffee is the most popular drink in the world, and we are understanding what benefit we can get from that.'
Previous studies have shown that coffee also cuts the risk of such chronic diseases as Parkinson's, prostate cancer, diabetes, Alzheimer's and age-related cognitive declines.
