Next time you can't make out a distant highway sign, blame your parents. Scientists in the United Kingdom have found that myopia, or nearsightedness, is predominantly hereditary, and they're beginning to unravel the genetic mechanism that causes the vision problem.
Roughly a third of people in the United States suffer from myopia—they clearly see close objects, such as words in a book, but things in the distance appear blurry. The anatomic root of the problem is an elongation of the eye as it grows, causing incoming light to focus in front of the retina, instead of squarely on it, explains Christopher J. Hammond of St. Thomas' Hospital in London.
Using a noninvasive technique, H