# Correlation Between Sunlight Exposure Time and Cataract Prevalence in Korean Adults
## 3 Results
\begin{table}
\begin{tabular}{c c c c} \hline
**Division** & **Classification** & **Frequency** & **Ratio (\%)** \\ \hline \multirow{3}{*}{Sunlight} & 2–5 h & 482 & 50.6 \\ \cline{2-4}  & Over 5 h & 470 & 49.4 \\ \hline \multirow{3}{*}{Gender} & Male & 522 & 54.8 \\ \cline{2-4}  & Female & 430 & 45.2 \\ \hline \multirow{3}{*}{Age} & Over 45 & 259 & 27.2 \\ \cline{2-4}  & Under 45 & 693 & 72.8 \\ \hline \multirow{3}{*}{Education Level (\(n=896\))} & Elementary School & 354 & 37.2 \\ \cline{2-4}  & Middle School & 136 & 14.3 \\ \cline{2-4}  & High School & 268 & 28.2 \\ \cline{2-4}  & University & 138 & 14.5 \\ \hline \multirow{3}{*}{Residence} & Seoul & 81 & 8.5 \\ \cline{2-4}  & Busan & 92 & 9.7 \\ \cline{2-4}  & Daegu & 90 & 9.5 \\ \cline{2-4}  & Incheon & 38 & 4.0 \\ \cline{2-4}  & Gwangju & 24 & 2.5 \\ \cline{2-4}  & Daejeon & 13 & 1.4 \\ \cline{2-4}  & Ulsan & 37 & 3.9 \\ \cline{2-4}  & Gyeonggi & 139 & 14.6 \\ \cline{2-4}  & Gangwon & 50 & 5.3 \\ \cline{2-4}  & Chungbuk & 47 & 4.9 \\ \cline{2-4}  & Chungnam & 21 & 2.2 \\ \cline{2-4}  & Jeonbuk & 47 & 4.9 \\ \cline{2-4}  & Jeonnam & 25 & 2.6 \\ \cline{2-4}  & Gyeongbuk & 137 & 14.4 \\ \cline{2-4}  & Gyeongnam & 96 & 10.1 \\ \cline{2-4}  & Jeju & 15 & 1.6 \\ \hline \multirow{3}{*}{Refractive Power (\(n=869\))} & Myopia & 303 & \(-\)2.03 D (Std. E. 0.120) \\ \cline{2-4}  & Hyperopia & 566 & 1.31 D (Std. E. 0.042) \\ \hline \end{tabular}
\end{table} 
Table 2: Sociodemographic analysis of study subjects. \(N=952\). Cross-tabulations were calculated to verify differences in cataract incidence rates by gender. As a result, in the 2-5 h group, there were 225 men (46.7%) and 257 women (53.3%), and in the 5 h or more group, there were 297 men (63.2%) and 173 women (36.8%). As a result of conducting a chi-square test to determine the statistical significance of the difference in cataract incidence rates between men and women according to the sunlight exposure time, the cataract incidence rate was 6.6% higher in women than men in the 2-5 h group, and in the group of more than 5 h, the rate in men was 26.4% higher than that in women, and this was statistically significant (Figure 2, Table 4). To determine the difference in cataract incidence by sunlight exposure and age, a cross-analysis was conducted by dividing the subjects into groups of people over 45 years old and under 45 years old. As a result, in the group exposed to sunlight for 2 to 5 h, 317 people (65.8%) were over 45 years old, and 165 people (34.2%) were under 45 years old. In the group exposed to sunlight for more than 5 h, 376 people (80.0%) were over 45 years old. Of these 376 people (80.0%), 94 people (20.0%) were under 45 years of age. A chi-square test was performed to determine whether the cataract incidence rate according to age was statistically significant. As a result, both the 2 to 5 h of sunlight exposure group and the 5 h or more of sunlight exposure group showed a statistically significantly higher incidence of cataracts after the age of 45 compared to before the age of 45 (Figure 3, Table 5). Figure 3: Cataract incidence rates according to age were divided into two groups. Figure 2: Cataract incidence rates according to gender were divided into two groups. Cros-tabulation analysis was conducted on 896 people (94.1%) out of a total of 952 people, excluding 56 people (5.9%) with missing data, to verify the difference in cataract incidence according to education level. As a result, in terms of sunlight exposure of 2 to 5 h, there were 143 (31.4%) elementary-school graduates, 72 (15.4%) middle-school graduates, 147 (32.3%) high-school graduates, and 93 (20.4%) university graduates. And in the group of 5 h or more, 211 people graduated from elementary school (47.8%) graduated from middle school, 64 people (14.5%) graduated from high school, 212 people (27.4%) graduated from high school, and 45 people (10.2%) graduated from university.