Purpose To analyze the variation of the objective refraction induced by pharmacological pupillary dilation in a normal population. Methods The objective refraction obtained by an auto-kerato-refractometer was analyzed before and after maximum pupillary dilation obtained by 0.5% Tropicamide and 10% Phenylephrine. 200 phakic eyes of 100 patients aged from 15 to 76 years were prospectively included. The refractive data were expressed in a dioptric space by 3 Cartesian coordinates (X, Y, Z). Results After pupil dilation, the mean refraction ranges from -0.08(+0.11)×90.2° to +0.41(+0.10)×90.3° this equal to an astigmatic vectorial variation of (+0.03)×89.6°. The spherical equivalent increases significantly (hyperopization of +0.49D: +0.24D vs +0.74D p