Purpose: To document the prevalence of visual impairment resulting from refractive error and to describe patterns of spectacle use in a representative sample of 12-year-old Australian school children.
Design: Population-based cross-sectional study.
Participants: Two thousand three hundred fifty-three predominantly 12-year-old children examined from 2004 through 2005.
Methods: Logarithm of the minimum angle of resolution (logMAR) visual acuity (VA) was measured unaided and with spectacles if worn. Subjective refraction, cycloplegic autorefraction (with cyclopentolate), and detailed dilated fundus examination were performed.
Main outcome measures: Myopia was defined as spherical equivalent (SE) refraction < or =-0.50 diopters (D), hyperopia as SE refraction > or =2.0 D, and astigmatism as cylinder > or =1.0 D. Uncorrected visual impairment was defined using unaided VA, and presenting visual impairment was defined using spectacle-corrected VA, if worn. Visual impairment was defined as VA <20/40 (<40 logMAR letters) for both better and worse eyes. Spectacle need was defined as uncorrected visual impairment in the better eye, improving by at least 2 lines with refraction, and undercorrection as presenting impairment in the better eye, improving by at least 2 lines with refraction.
Results: Uncorrected and presenting visual impairment in at least 1 eye because of refractive error was found in 10.4% and 3.7%, respectively. Spectacle use was reported by 448 children (19.0%); 204 (46.3%) had myopia, 48 (10.9%) had hyperopia, and 96 (21.8%) had astigmatism in at least 1 eye; 38.3% had no significant refractive error in either eye. Eight children were in need of spectacles and 37 children (8.3% of spectacle users) were undercorrected. Nonrefractive spectacle users were more likely to report eyestrain and headache or to have had learning difficulty at school (P<0.0001).
Conclusions: This study documents a relatively low prevalence of undercorrected refractive error in a population of Australian children. Nonrefractive prescription of spectacles is common.