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. 2006 Jan;90(1):40–43. doi: 10.1136/bjo.2005.072009

Table 2 Mean, standard deviation (SD), and 95% confidence limits (mean (SD 2.00) for right and left eye visual acuity and interocular difference (IAD) for children categorised as having a normal refraction.

Analysis 3 year olds (n = 84) 4 year olds (n = 45)
Right eye Left eye Right eye Left eye
Mean acuity (SD) 0.200 (0.09) 0.200 (0.08) 0.140 (0.08) 0.144 (0.07)
Median acuity 0.180 0.200 0.100 0.125
95% confidence limits 0.020 to 0.380 0.040 to 0.360 −0.02 to 0.300 0.004 to 0.284
Percentiles limits 0.075 to 0.400 0.078 to 0.400 0.008 to 0.325 0.000 to 0.300
Mean IAD (SD) 0.03 (0.06) 0.03 (0.04)
Median IAD 0.00 0.025
95% confidence limits IAD −0.09 to 0.150 −0.05 to 0.110
Percentiles limits IAD 0.00 to 0.262 0.000 to 0.167

As the data were not normally distributed the median value and percentile limits (2.5th to 97.5th percentile) are also presented.