The incidence of myopia in the United States has risen drastically—66%—since 1971, say researchers from the National Eye Institute.

Using data from the National Health and Nutrition Examination Survey (NHANES), researchers measured myopia rates in a population aged 12 to 54 in 1971-1972 and in 1999-2004. Results were published in the December 2009 Archives of Ophthalmology.

In this study, 4,436 patients within the early cohort and 8,339 from the modern cohort were included. Researchers found that the prevalence of myopia increased significantly—from 25% of the patient population in 1971-1972 to 41.6% in 1999-2004—an increase of 66.4%.

Myopia nearly doubled in black patients across all age groups. White patients between the ages of 12 and 24 had a 30% increase in myopia, while it was 80.8% higher in white patients between the ages of 25 and 54. Also, myopia ranged from 25.7% to 59.8% higher in patients with 12 or more years of formal education.

Regardless of myopia’s management, these figures point toward a deeper problem regarding financial expenditures, say researchers. “If 25% of those aged 12 to 54 years had myopia, the associated annual cost would be more than $2 billion,” they write. “An increase to 37% would increase the cost to more than $3 billion.”