Table 1.

Prevalence of errors of visual acuity of children as per class studied

Class studied	Boys		Girls		Total		95% CI
No. examined	No. with defective vision	No. examined	No. with defective vision	No. examined	No. with defective vision
V	16	2	18	0	34	2	-2.03
		(12.5%)				(5.88%)	13.79
VI	29	6	17	8	46	14	17.14
		(20.69%)		(47.06%)		(30.43%)	43.73
VII	29	6	25	7	54	13	12.67
		(20.69%)		(28.00%)		(24.07%)	35.48
VIII	15	1	16	3	31	4	1.10
		(6.67%)		(18.75%)		(12.90%)	24.70
IX	20	8	22	5	42	13	16.97
		(40.00%)		(22.73%)		(30.95%)	44.93
X	17	2	12	2	29	4	1.24
		(11.76%)		(16.67%)		(13.79%)	26.34
Total	126	25	110	25	236	50	15.97
		(19.84%)		(22.73%)		(29.19%)	26.40

χ² (boys, girls) = 0.29, df = 1, p>0.05, χ² for linear trend = 0.281, p>0.05