Table 3.

Total SER and SER values stratified by sex and age

Age (N)	SER (D)			t	P value
	Total	Boys	Girls
3 (159)	+ 0.32 ± 1.01	+ 0.22 ± 1.29	+ 0.42 ± 0.60	-1.21	0.228
4 (235)	+ 0.22 ± 0.82	+ 0.17 ± 0.85	+ 0.29 ± 0.76	-1.17	0.243
5 (234)	+ 0.37 ± 0.54	+ 0.35 ± 0.60	+ 0.39 ± 0.45	-0.514	0.608
6 (2304)	+ 0.22 ± 0.89	+ 0.22 ± 1.03	+ 0.21 ± 0.73	0.315	0.753
7 (2936)	-0.03 ± 0.95	-0.04 ± 0.92	-0.01 ± 0.98	-0.733	0.463
8 (2621)	-0.40 ± 1.14	-0.40 ± 1.21	-0.39 ± 1.06	-0.275	0.783
9 (2431)	-0.71 ± 1.31	-0.65 ± 1.33	-0.76 ± 1.29	2.072	0.038*
10 (2336)	-1.13 ± 1.59	-1.07 ± 1.52)	-1.20 ± 1.66	2.088	0.037*
11 (2210)	-1.48 ± 1.79	-1.41 ± 1.83	-1.56 ± 1.74	2.048	0.041*
12 (1623)	-1.96 ± 2.07	-1.85 ± 2.08	-2.07 ± 2.05	2.118	0.034*
13 (1429)	-2.36 ± 2.10	-2.30 ± 2.11	-2.43 ± 2.10	1.11	0.267
14 (937)	-2.71 ± 2.32	-2.53 ± 2.35	-2.90 ± 2.26	2.398	0.017*

N: number, D: dioptres, * represents P < 0.05, **represents P < 0.001