The Bulletin of the World Health Organization recently published the results of the first study to estimate the productivity loss from uncorrected refractive error—common vision problems that can easily be treated with eyeglasses, contact lenses, or laser surgery. But left untreated, these simple challenges can lead to virtual blindness for sufferers. And the researchers who conducted the study estimate these vision issues cost the world at least $269 billion in lost productivity each year.

Even using conservative estimates, the researchers believe uncorrected refractive error could potentially have a greater impact on the global economy than all other preventable vision disorders.

Hardest hit by this global crisis is the Western Pacific region, including China and Vietnam, with 62 million untreated cases. The Southeast Asia region, including Bangladesh, India, and Nepal, has nearly 49 million cases. But 60 percent of Americans also suffer refractive vision problems, and it’s estimated that 11 million Americans go untreated. Unfortunately, only 17 percent of U.S. employers offer vision insurance, although the Vision Council reports that for every $1 spent on vision coverage, employers gain up to $7 in productivity and other assets. The council also reports that uncorrected vision problems cost American employers $8 billion a year in lost productivity.

Are you suffering from a correctable vision disorder? Here are the four types of refractive errors as defined by the American Academy of Ophthalmology:

• Hyperopia or farsightedness. Objects at a distance are clear, but words on a page are blurred; it’s difficult to thread a needle.

• Myopia or nearsightedness. Close objects look clear, but objects at a distance seem blurred.

• Astigmatism. Vision is distorted or blurred for both near and far objects.

• Presbyopia. A condition which often begins at about age 40 and affects reading as the eyes gradually lose the ability to change focus from far to near.