U.S. researchers say over one million Americans over the age of 40 are blind and two and a half million are visually impaired. They say these numbers could double over the next thirty years as the population ages. U.S. researchers are calling for more government help and private investment to reduce blindness.
The National Eye Institute in Washington says there are four leading causes of vision impairment among the country's aging population.
Diabetic retinopathy is blood leakage in the eye's retina due to diabetes. This is especially prevalent among African-Americans and Hispanic-Americans.
Macular degeneration, an internal atrophy of the eye, is found mostly among the Caucasian population. Glaucoma affects the eye's optic nerve. And finally, the leading cause of blindness is cataract - which is basically progressive vision clouding.
James Tielsch, a board member with the volunteer group Prevent Blindness America, says it's time to bring down the burden of blindness.
"For some of these diseases right now, we just have no effective therapeutic approaches," he said. "We need lots of good research. We need to be able to implement the screening and prevention programs that we know work now. We need to invest in those now to get those gains that are going to happen in the next 20 to 30 years."
Researchers say they would like to establish a new vision program at Atlanta's federal Centers for Disease Control and Prevention to help the country's old. They say more needs to be done to make treatment, rehabilitation and prevention for eye illnesses accessible and affordable.
Nathan Congdon, a researcher at the Johns Hopkins University in Baltimore, Maryland, says this is applicable elsewhere in the world.
"Populations throughout the world, not just here but in Asia, Africa are aging and diseases of aging like cataract - classically - or glaucoma are going to be increasing problems in those parts of the world, no question about it," he said. "And I think diseases like river blindness, vitamin A deficiency, trachoma, many of those we've got magic bullets for good solutions to."
For the time being, diabetic retinopathy which is related to too much sugar in one's diet is more prevalent in the United States than elsewhere, but researchers say this type of lifestyle is spreading to other parts of the world. They say people with diabetes should exercise more and eat less sugar to avoid going blind.
The World Health Organization in Geneva is leading global efforts to wipe out preventable blindness by 2020.