No 14,464 583 1,385 1,448 1,543 2,138 2,197 1,852 1,787 1,531 No 14,489 580 1,387 1,451 1,546 2,141 2,203 1,853 1,791 1,537 Total Prev (%) 1.5 1.8 1.8 1.9 1.5 1.7 1.0 1.4 1.6 1.9 Total Prev (%) 11.0 9.9 11.1 9.1 5.0 4.1 6.7 15.0 22.5 35.2 SE (0.1) (0.7) (0.3) (0.4) (0.4) (0.3) (0.2) (0.3) (0.3) (0.5) SE (0.8) (1.6) (1.6) (1.2) (0.9) (0.7) (0.9) (1.5) (1.7) (2.3) No 6,517 314 725 756 687 898 942 797 776 622 No 6,530 313 726 757 687 899 946 798 778 626 Male Prev (%) 1.5 0.5 1.7 1.7 1.1 2.1 1.0 1.5 2.2 2.2 Male Prev (%) 12.1 10.1 13.4 12.5 7.6 5.6 8.9 16.5 20.9 33.2 SE (0.2) (0.4) (0.4) (0.6) (0.4) (0.5) (0.3) (0.4) (0.5) (0.7) SE (0.9) (2.1) (2.0) (1.7) (1.4) (1.0) (1.3) (1.7) (2.0) (2.8) Total 3-5 6-11 12-18 19-29 30-39 40-49 50-59 60-69 ≥70 Total 3-5 6-11 12-18 19-29 30-39 40-49 50-59 60-69 ≥70 No 7,947 269 660 692 856 1,240 1,255 1,055 1,011 909 No 7,959 267 661 694 859 1,242 1,257 1,055 1,013 911 Korean J Ophthalmol Vol.25, No.6, 2011 Table 3. Prevalence of refractive errors according to age Age group (yr) Total 5-11 12-18 19-29 30-39 40-49 50-59 60-69 ≥70 No 13,636 1,560 1,429 1,529 2,091 2,147 1,786 1,702 1,392 Myopia Prev (%) 53.7 50.0 78.8 75.3 67.4 51.1 29.3 18.2 28.4 SE (0.6) (1.5) (1.3) (1.2) (1.2) (1.3) (1.3) (1.1) (1.2) No 13,636 1,560 1,429 1,529 2,091 2,147 1,786 1,702 1,392 Hyperopia Prev (%) 10.7 5.3 2.5 1.9 1.1 3.1 16.5 43.8 47.1 SE (0.4) (0.6) (0.4) (0.4) (0.3) (0.4) (1.0) (1.5) (1.5) Myopia was defined as spherical equivalents of worse than -0.75 diopter. Hyperopia was defined defined as spherical equivalents of worse than +1.0 diopter. Astigmatism was defined as a cylindrical error worse than +0.75 diopter. No = number of participants; Prev = prevalence; SE = standard error. Table 4. Prevalence of strabismus according to age and gender Age group (yr) Strabismus was defined as a heterotropia at distance and/or near fixation with or without spectacle correction, esodeviation of 10 or more prism diopters, exodeviation of 15 or more prism diopters, or any vertical deviation. No = number of participants; Prev = prevalence; SE = standard error. Table 5. Prevalence of blepharoptosis according to age and gender Age group (yr) Blepharoptosis was defined as a marginal reflex distance 1 of 2 mm or less. No = number of participants; Prev = prevalence; SE = standard error. males, 3.4 ± 1.4% in females), and it was higher in females than in males (p < 0.01). There were no significant differ- ences in relation to age (p > 0.05). The overall prevalence of esodeviation, exodeviation and vertical deviation was 0.2 ± 0.0%, 1.1 ± 0.1% and 0.3 ± 0.0%, respectively. Blepharoptosis The overall prevalence of blepharoptosis was 11.0 ± 0.8% (12.1 ± 0.9% in males, 10.0 ± 0.8% in females) (Table 5 and Fig. 2). The prevalence of blepharoptosis in participants over 426 No 13,636 1,560 1,429 1,529 2,091 2,147 1,786 1,702 1,392 Female Prev (%) 1.5 3.4 1.9 2.1 2.0 1.2 0.9 1.3 1.1 1.8 Female Prev (%) 10.0 9.7 8.6 5.4 2.2 2.5 4.5 13.5 24.0 36.4 Astigmatism Prev (%) 58.0 38.7 61.6 53.9 49.5 51.8 63.0 79.4 92.0 SE (0.2) (1.4) (0.6) (0.5) (0.6) (0.3) (0.3) (0.4) (0.4) (0.6) SE (0.8) (2.3) (1.5) (0.9) (0.7) (0.5) (0.8) (1.9) (1.9) (2.6) SE (0.6) (1.4) (1.6) (1.4) (1.3) (1.4) (1.3) (1.1) (0.8) p-value 0.93 0.01 0.75 0.65 0.18 0.09 0.86 0.68 0.07 0.69 p-value <0.01 0.01 <0.01 <0.01 <0.01 <0.01 <0.01 0.16 0.16 0.26