Strabismus affects any age and represents various functional or non-functional eye problems. This population-based study was conducted to determine the prevalence of strabismus and nystagmus in South Korea according to various sociodemographic factors.

We acquired data from the Korea National Health and Nutrition Examination Survey, a nation-wide cross-sectional survey and examinations of the non-institutionalized civilian population in South Korea (n = 30,538), conducted from July 2008 to December 2011. The prevalence of strabismus and nystagmus were verified, and associated sociodemographic factors was evaluated.

The overall prevalence of strabismic disorder in participants over 3 years of age was 1.4 ± 0.1% (95% confidence interval [CI] 1.3–1.6%; 1.5 ± 0.1% in males, 1.3 ± 0.1% in females). The prevalence of exodeviation (15 or more prism diopters), esodeviation (10 or more prism diopters), vertical deviation, and other complicated strabismus and nystagmus was 1.0%, 0.2%, 0.2%, 0.1% and 0.1% respectively. The prevalence was highest in the 6 to 15-year age group (1.9 ± 0.3%), and lowest in the 40 to 49 years age group (0.8 ± 0.1%) ( p = 0.005). There were no statistically significant differences for gender, region, residential area, household income, educational level and occupation.

This nation-wide epidemiologic study demonstrated that the prevalence of strabismus and nystagmus according to various sociodemographic factors in South Korea was not statistically significant except for age group. Further investigations are required based on more surveys to better recognize the etiologic or risk factors that may be related to strabismus and nystagmus.