Dr. Shambhu D. Varma of the University of Maryland School of Medicine has found that caffeine can prevent cataracts in rats. Dr. Varma treated rat pups with sodium seramide, a chemical that causes cataracts in the pups. While the control group all developed cataracts, the rat pups that were also given caffeine did not.
Cataracts are responsible for about half of all cases of blindness and while they can be treated with cataract surgery, no strategy for cataract prevention has yet been proven safe and effective. Caffeine, a bioflavonoid present in coffee and tea, prevents cataracts by inhibiting oxidative stress caused by oxygen radicals and by inhibiting the cataract-causing enzyme aldose reductase.
However, caffeine treatment for cataract prevention is not yet viable for humans as the dosage administered to Dr. Varma’s rat pups was quite high. Dr. Varma estimates that a human would need to consume about half a gram of pure caffeine (equivalent to 6.25 cups of coffee) daily to achieve the same effect. Dr. Varma is currently working on a more direct delivery system that works with a smaller dosage for use in humans. Caffeinated eye drops seem to be the most likely to work in people.
For more information on cataracts, find a qualified ophthalmologist in your area.