Editing Myopia (section)

===North America===
Myopia is common in the [[United States]], with research suggesting this condition has increased dramatically in recent decades. In 1971–1972, the National Health and Nutrition Examination Survey provided the earliest nationally representative estimates for myopia prevalence in the U.S., and found the prevalence in persons aged 12–54 was 25%. Using the same method, in 1999–2004, myopia prevalence was estimated to have climbed to 42%.<ref name="Vitale">{{cite journal | vauthors = Vitale S, Sperduto RD, Ferris FL | title = Increased prevalence of myopia in the United States between 1971–1972 and 1999–2004 | journal = Archives of Ophthalmology | volume = 127 | issue = 12 | pages = 1632–9 | date = December 2009 | pmid = 20008719 | doi = 10.1001/archophthalmol.2009.303 | doi-access = free }}</ref>

A study of 2,523 children in grades 1 to 8 (age, 5–17 years) found nearly one in 10 (9%) have at least −0.75 diopters of myopia.<ref name="pmid12912692">{{cite journal | vauthors = Kleinstein RN, Jones LA, Hullett S, Kwon S, Lee RJ, Friedman NE, Manny RE, Mutti DO, Yu JA, Zadnik K | display-authors = 6 | title = Refractive error and ethnicity in children | journal = Archives of Ophthalmology | volume = 121 | issue = 8 | pages = 1141–7 | date = August 2003 | pmid = 12912692 | doi = 10.1001/archopht.121.8.1141 | doi-access = free }}</ref> In this study, 13% had at least +1.25 D [[hyperopia]] (farsightedness), and 28% had at least 1.00-D difference between the two principal meridians (cycloplegic autorefraction) of [[astigmatism]]. For myopia, Asians had the highest prevalence (19%), followed by Hispanics (13%). Caucasian children had the lowest prevalence of myopia (4%), which was not significantly different from African Americans (7%).<ref name="pmid12912692" />

A recent review found 25% of Americans aged 40 or older have at least −1.00 diopters of myopia and 5% have at least −5.00 diopters.<ref name="pmid15078666" />