As a particular test of visual function, contrast sensitivity reveals optical properties of Iogel pHema lenses in comparison to poly(methyl methacrylate) implants (PMMA). Sixteen patients with a hydrogel posterior chamber lens in one eye and a PMMA posterior chamber lens in the other were examined by means of contrast sensitivity measurements. Six stationary, vertical, sinusoidal modulated gratings with spatial frequencies of 0.5, 1, 3, 6, 11.4 and 22.8 cycles/degree were presented. Results of the two different implants were analyzed by a paired t-test. There was no significant statistical difference between the two types of lenses for any of the gratings presented. Despite different features like material, refractive index, design and UV-absorbing additive, there seems to be no difference between lenses made of hydrogel and those made of PMMA material with regard to functional vision as evaluated by contrast sensitivity testing.