Table 5.

Analysis of Decentration Tolerance (Maximum Permissible Decentration to Maintain a Threshold Value)

		r̄ (μ m)		SD of r̄ (μm) (CV of r̄ [%])
Parameter	Threshold Value	3.5-mm PD	6-mm PD	3.5-mm PD	6-mm PD
Δ2nd-order sphere	−0.5 D	1255 ± 160	1313 ± 136	228 ± 60 (19 ± 7)	111 ± 47 (8 ± 3)
Δ2nd-order cylinder	−0.5 D	1304 ± 130	1008 ± 214	208 ± 64 (16 ± 6)	173 ± 102 (16 ± 8)
ΔVSOTF sphere	−0.5 D	1348 ± 104	1232 ± 314	204 ± 63 (15 ± 6)	246 ± 55 (20 ± 5)
ΔVSOTF cylinder	−0.5 D	1289 ± 201	1167 ± 271	226 ± 100 (19 ± 13)	207 ± 63 (20 ± 12)
Δlog BCVSOTF	−0.2	1219 ± 210	800 ± 512	248 ± 82 (21 ± 8)	143 ± 40 (21 ± 8)

The radius r̄ is the mean length of the vectors between the center and the locations with threshold values. The SD and CV of r̄ reflect the irregularity of the decentration behavior. All data are expressed as the mean and SD. PD, analysis pupil diameter. VSOTF sphere/cylinder, simulated endpoint of the subjective refraction based on the BCVSOTF.