# Correlation Between Sunlight Exposure Time and Cataract Prevalence in Korean Adults
## 3 Results
As a result of conducting the chi-square test to find out the statistical significance of the cataract incidence rate due to the difference in the curriculum according to the exposure time of sunlight, the cataract incidence rate was higher for university graduates than for elementary-school graduates in the 2-5 h group. And in the group over 5 h, elementary-school graduates were higher than university graduates and were statistically significant. However, middle- and high-school graduates showed no significant difference between the 2-5 h group and the 5 h or more group (Figure 4, Table 7). \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Dependent** & **Independent** & **B** & **S.E.** & **OR** & **95\% CI** & \(p\) \\
**Variable** & **Variable** & & & & & \\ \hline Prevalence & Age & 0.160 & 0.010 & 1.173 & (1.150–1.197) & \textless{}0.001 \\ \hline \hline \end{tabular} \(-\)2 LL = 743.781, Nagelkerke R\({}^{2}\) = 0.605, Hosmer and Lemeshow Test: x\({}^{2}\) = 8.872 (_p_ = 0.353).  
\end{table} 
Table 6: Increasing age affects the development of cataracts. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**0.001**} & \multirow{2}{*}{**} & \multicolumn{3}{c}{**Sun Exposure**} & \multirow{2}{*}{**Total**} & \multirow{2}{*}{**x\({}^{2}\)**} & \multirow{2}{*}{_p_} \\ \cline{3-3} \cline{5-7}  & & **2-5 h** & & & & \\ \hline Prevalence & Over 45 & 317 (65.8) & 376 (80.0) & 693 (72.8) & & \\ \cline{2-7} of cataract & Under 45 & 165 (34.2) & 94 (20.0) & 259 (27.2) & 24.339 & \textless{}0.001 *** \\ \hline Total & 482 (100) & 470 (100) & 952 (100) & & & \\ \hline \hline \end{tabular} \(p\)** \(<\) 0.001, \(p\)*** \(<\) 0.001, Unit: Frequency (%).  
\end{table} 
Table 5: Frequency of cataracts according to age. As shown in Figure 5, cross-tabulation analysis was performed to determine the differences in cataract incidence according to sunlight exposure and place of residence. As a result, in the group exposed to sunlight for 2 to 5 h, there were 52 people (10.8%) in the Seoul area and 63 people (13.1%) in the Busan area. In the group exposed to sunlight for more than 5 h, 36 people (7.7%) were in the Gangwon region and 85 people (18.1%) were in the Gyeongbuk region. A chi-square test was performed to determine the incidence of cataracts according to residential area. As a result, in the 2 to 5 h group, the cataract incidence rate was high in large cities such as Seoul and Busan, and in the 5 h or more group, the cataract incidence rate was significantly higher in rural areas such as Gangwon and Gyeongbuk. Figure 4: Cataract incidence rates according to education level were divided into two groups. Figure 5: Cataract incidence rates according to region of residence were divided into two groups. In this analysis, the exposure time of sunlight in Koreans was significantly associated with increased cataract prevalence for over 5 h of exposure (54.7%). In addition, the analysis of cataract prevalence according to the sunlight exposure time confirmed that the majority of Korean adults suffer from nuclear cataracts (67.8%). The 2-5 h group of sunlight exposure was found to be significantly associated with an increase in the cataract discrimination rate in women (53.3%), university graduates (20.4%), and those in urban areas (Seoul 10.8%, Busan 13.1%). On the other hand, in the group with more than 5 h of sunlight exposure, it was found that the cataract prevalence increased in men (63.2%), elementary-school graduates (47.8%), and those in rural areas (Gangwon 7.7%, Gyeongbuk 18.1%). However, the prevalence of cataracts significantly increased after age 45 in people with both 2-5 h and 5 h of sunlight exposure.