Also, a separate study finds about half of the American population has poor eyesight. That's far higher than previous estimates. The study in the Archives of Ophthalmology finds the most common problems are nearsightedness or astigmatism. The cause of these eye conditions is still unclear, but it's believed genetics plays a role.
Study: Half of Americans have bad vision
A new study finds the eyes can reveal damage to tiny blood vessels long before symptoms of heart disease ever start. The study in the journal Heart found people with a type of eye damage known as retinopathy were more likely to die of heart disease over the next 12 years than those without it.