KC Yoon, et al. Prevalence of Eye Disease in South Korea Table 6. Prevalence of cataract according to age and gender Age group (yr) Total 19-29 30-39 40-49 50-59 60-69 ≥70 No 11,037 1,542 2,137 2,198 1,850 1,785 1,525 Total Prev (%) 24.1 1.1 2.5 10.3 33.8 69.4 93.7 SE (0.9) (0.3) (0.4) (1.1) (2.0) (2.1) (0.8) No 4,718 685 898 943 797 774 621 Male Prev (%) 21.9 0.9 2.8 10.6 35.1 67.4 90.9 SE (1.0) (0.4) (0.7) (1.3) (2.7) (2.7) (1.6) Any cataract in at least one eye: pseudophakic and aphakic eyes were also included as cataract. No = number of participants; Prev = prevalence; SE = standard error. Fig. 2. Prevalence of blepharoptosis ac- cording to age and gender. No 6,319 857 1,239 1,255 1,053 1,011 904 Female Prev (%) 26.2 1.3 2.2 10.0 32.5 71.2 95.4 SE (1.0) (0.5) (0.4) (1.3) (2.2) (2.2) (0.8) p-value <0.01 0.49 0.34 0.66 0.31 0.12 <0.01 Fig. 3. Prevalence of cataract according to age and gender. 40 years of age was 16.2 ± 1.1%. From the age of 40, the prevalence of blepharoptosis was increased with age, and it was highest in the age group over 70 years (35.2 ± 2.3%, p < 0.01). The prevalence of blepharoptosis was higher in males than in females in participants from 6 to 49 years of age (p < 0.05). Cataract The prevalence of cataract in participants over 19 years of age was 24.1 ± 0.9% (21.9 ± 1.0% in males, 26.2 ± 1.0% in females) (Table 6 and Fig. 3), that in participants over 40 years of age was 40.2 ± 1.3% (37.5 ± 1.5% in males, 42.6 ± 1.3% in females), and that in participants over 60 years of age was 80.5 ± 1.3% (76.9 ± 1.8% in males, 83.2 ± 1.3% in fe- males). These results indicate that prevalence of cataract tended to increase with age (p < 0.01). The prevalence of cat- aract in participants over 40 years of age was higher in fe- males than in males (p < 0.01). Pterygium The prevalence of pterygium in participants over 19 years of age was 5.4 ± 0.3% (6.1 ± 0.5% in males, 4.7 ± 0.3% in fe- males) (Table 7 and Fig. 4). The prevalence of pterygium in participants over 40 years of age was 8.9 ± 0.5% (10.1 ± 0.8% in males, 7.7 ± 0.5% in females), while that in partic- ipants over 60 years of age was 16.0 ± 0.8% (17.7 ± 1.3% in 427