Table 3.

Perceived causes of myopia.

	Total	Primary	Middle	High School
Reading	3.71 (1.18)	3.74 (1.21)	3.65 (1.10)	3.63 (1.15)
TV	3.57 (1.35)	3.67 (1.32)	3.27 (1.49)	3.61 (1.26)
Outdoor activities	3.80 (1.20)	3.86 (1.17)	3.61 (1.27)	3.78 (1.14)
Sleep	3.45 (1.31)	3.36 (1.31)	3.48 (1.37)	3.85 (1.10)
Genetics	3.45 (1.26)	3.54 (1.26)	3.44 (1.22)	3.00 (1.20)
Space	2.89 (1.22)	2.93 (1.23)	2.94 (1.20)	2.56 (1.16)
Injury	2.24 (1.31)	2.25 (1.30)	2.14 (1.31)	2.38 (1.34)

Note: All values are reported on the 5-point Likert scale. Numbers in parentheses represent ± standard deviation. Space refers to respondents’ consciousness about their living space. A higher value means more concern that their living conditions are not spacious enough and are harmful to their (or their children’s) vision.