Table 3. Multiple logistic regression analysis of eye disorder according to hours of sunlight exposure (KNHANES 2010–2012).

Sun exposure level		Total				Male				Female
		No. of participants		OR (95% CI)	p for trend	No. of participants		OR (95% CI)	p for trend	No. of participants		OR (95% CI)	p for trend
Cataract		No	Yes		0.189	No	Yes		0.117	No	Yes		0.974
	Sunlight exposure < 2 hr	3,025	736	1.00 (Reference)		1,454	392	1.00 (Reference)		1,571	344	1.00 (Reference)
	2 hr ≤ sunlight exposure < 5 hr	1,102	338	0.85 (0.70–1.03)		677	202	0.78 (0.61–1.01)		425	136	0.97 (0.72–1.31)
	Sunlight exposure ≥ 5 hr	600	537	1.01 (0.83–1.23)		394	318	1.01 (0.78–1.30)		206	219	1.01 (0.74–1.37)
Pterygium		No	Yes		< 0.001	No	Yes		0.159	No	Yes		< 0.001
	Sunlight exposure < 2 hr	3,601	160	1.00 (Reference)		1,765	81	1.00 (Reference)		1,836	79	1.00 (Reference)
	2 hr ≤ Sunlight exposure < 5 hr	1,360	80	1.07 (0.80–1.43)		836	43	0.90 (0.61–1.34)		524	37	1.28 (0.83–1.97)
	Sunlight exposure ≥ 5 hr	960	177	1.62 (1.25–2.08)		622	90	1.30 (0.91–1.86)		338	87	2.00 (1.39–2.88)
AMD		No	Yes		0.311	No	Yes		0.333	No	Yes		0.693
	Sunlight exposure < 2 hr	3,644	117	1.00 (Reference)		1,785	61	1.00 (Reference)		1,859	56	1.00 (Reference)
	2 hr ≤ Sunlight exposure < 5 hr	1,366	74	1.27 (0.93–1.74)		831	48	1.36 (0.91–2.05)		535	26	1.25 (0.75–2.08)
	Sunlight exposure ≥ 5 hr	1,024	113	1.17 (0.87–1.58)		647	65	1.17 (0.78–1.76)		377	48	1.12 (0.71–1.77)

Results were adjusted for age, sex, household income, education level, occupational classification, alcohol consumption, current smoking status, physical activity, obesity, hypertension, and diabetes mellitus. Each sex-stratified analysis was not adjusted for sex. Bold-faced values are statistically significant (p < 0.05).

KNHANES: Korea National Health and Nutrition Examination Survey; OR: odds ratio; CI: confidence interval; AMD: age-related macular degeneration.