Myopia, or nearsightedness, is a common eyesight condition, which affects more Americans today than three decades ago. Susan Vitale, from the National Eye Institute at the US  National Institutes of Health (Maryland, USA), and colleagues compared cases of myopia in the United States for the period of 1971-1972 versus 1999-2004, examining data from two National Health and Nutrition Examination Surveys to determine whether myopia prevalence had changed during the 30 years between the two survey periods.  Using the 1971-1972 method, the researchers found that the estimated prevalence of myopia in persons aged 12 to 54 years was significantly higher in 1999-2004 than in 1971-1972.  In other words, the prevalence of myopia increased from 25% in 1971-1972 to 41.6% in 1999-2004, with the incidence jumping from 13% to 33.5% among blacks, and 26.3% to 43% among whites.  The team urges that: “The prevalence of myopia in the United States appears to be substantially higher in 1999-2004 than 30 years earlier. Identifying modifiable risk factors for myopia could lead to the development of cost-effective interventional strategies.”