Clinical assessment of chromatic aberration in phakic and pseudophakic eyes using a simple autorefractor.

We describe a psychophysical method and a simple setup - an autorefractor with a Scheiner disc, sequentially illuminated with red and blue lights - for the clinical assessment of the longitudinal chromatic aberration (LCA) in phakic and pseudophakic patients. This method applies to the unaccommodated eye, even in the presence of positive or negative refractive errors and astigmatism. It measures the chromatic difference of refraction as an estimate of LCA. We built a proof of concept from inexpensive and off-the-shelf optomechanical components with which we obtained the preliminary clinical results presented in the paper. We considered one control group of phakic patients and three groups of pseudophakic patients with monofocal implants of different designs and materials. The results, satisfactory and consistent with those reported by other researchers in related works, demonstrate the method and system feasibility.