Prevalence and Related Factors for Myopia in School-Aged Children in Qingdao

Table 4

Near work and outdoor activity time (hours per day) of the students.

Age (years)	n	Near work (h/d)	Outdoor activity (h/d)
		(Mean ± SD)	(Mean ± SD)
10	562	3.32 ± 1.32	2.28 ± 1.21
11	559	3.42 ± 1.56	2.24 ± 1.26
12	536	3.41 ± 1.82	2.06 ± 1.32
13	561	3.78 ± 1.42	1.88 ± 1.12
14	752	4.32 ± 1.84	1.64 ± 1.14
15	783	4.62 ± 1.26	1.42 ± 0.96
value