Contrast sensitivity was measured in pseudophakic and aphakic patients. No difference could be demonstrated between the contrast sensitivities of patients with anterior chamber/iris-supported and posterior chamber intraocular lenses (IOLs). Little difference was found between pseudophakics and aphakics. Interocular contrast ratios in five pseudophakic patients with normal fellow eyes revealed a range of contrast attenuation characteristics which may be attributed to the IOL and corneal and posterior capsule transmission.