Increased Prevalence of Myopia in the United States Between 1971-1972 and 1999-2004

To compare US population prevalence estimates for myopia in 1971-1972 and 1999-2004.

The 1971-1972 National Health and Nutrition Examination Survey provided the earliest nationally representative estimates for US myopia prevalence; myopia was diagnosed by an algorithm using either lensometry, pinhole visual acuity, and presenting visual acuity (for presenting visual acuity > or =20/40) or retinoscopy (for presenting visual acuity -2.0 diopters [D]: 17.5% vs 13.4%, respectively [P -7.9 D: 22.4% vs 11.4%, respectively [P