We present a Purkinje imaging system for phakometry and measurement of tilt and decentration of crystalline and intraocular lenses (IOLs). Crystalline lens radii of curvature were estimated by using both a merit function and the equivalent mirror approaches. Tilts and decentrations were estimated by using Phillips’s linear analysis. We present a complete validation of the technique through exhaustive computer simulations and control experiments, and measurements in 17 normal eyes (mean age $26.67\pm 2.31$ ) and nine postcataract surgery eyes (mean age $74\pm 2.3$ ). Crystalline lens radii ranged from 12.7 to 8.81 mm and from $-5.64$ to $-7.09\mathrm{mm}$ for anterior and posterior surfaces, respectively. Crystalline lens tilt ranged from 2.8 to $-2.87\mathrm{deg}$ horizontally and from 2.58 to $-1\mathrm{deg}$ vertically. Crystalline lens decentration ranged from 0.09 to 0.45 mm horizontally and from 0.09 to $-0.22\mathrm{mm}$ vertically. IOL tilt ranged from 3.6 to $-1.51\mathrm{deg}$ horizontally and from 5.97 to $-1.85\mathrm{deg}$ vertically. IOL decentration ranged from 0.53 to $-0.31\mathrm{mm}$ horizontally and from 0.13 to $-0.96\mathrm{mm}$ vertically.