Correlation Between Sunlight Exposure Time and Cataract Prevalence in Korean Adults

This study analyzed the survey data of the ophthalmic examination of the 5th National Health and Nutrition Examination Survey to investigate the relationship between the prevalence of cataracts in Koreans and exposure to sunlight in daily life. From January to December, 952 people in 192 districts were classified into a 2–5 h group and a group of more than 5 h of sunlight exposure, and statistical analysis using SMS version 26, including the chi-square test and logistic regression analysis, was conducted. Results: The gender difference was that women had a higher incidence of cataracts when the exposure time to sunlight was 2 to 5 h (46.7% for men, 53.3% for women, p < 0.001) and men had a higher incidence of cataracts when it was more than 5 h (62.3% for men, 36.8% for women, p < 0.001). The incidence increased significantly after age 45 for the groups of both 2 to 5 h (65.8% for men, p < 0.001) and 5 h or more (80% for p < 0.001) of sunlight exposure. In the group with 2 to 5 h of sunlight exposure, the prevalence of cataracts was high in people living in large cities, such as 52 people in Seoul (10.8%) and 63 people in Busan (13.1%), while in the group with 5 h or more, the incidence of cataracts was significantly higher in people living in rural areas, such as 36 people in Gangwon Province (7.7%) and 85 people in North Gyeongsang Province (18.1%). Through this, it was confirmed that Koreans had a higher incidence of cataracts when exposed to sunlight for more than 5 h, and differences according to socio-demographic characteristics could be identified in the case of a sunlight exposure time of 2 to 5 h or more.