The optical quality of currently manufactured intraocular lenses.

We selected 95 intraocular lenses from ten lens manufacturers for a study of optical quality. Tremendous variation in resolution from a high of 313 line pairs per millimeter to a low of 40 line pairs per millimeter was seen. All of the lenses from eight manufacturers showed greater than 100 line pairs per millimeter resolution, the American National Standards Institute proposed minimum. Five of the 95 lenses had greater than 1.0 diopter error, whereas 79 of the 95 lenses had less than 0.5 diopter error from the stated power. With respect to toricity, there were 11 lenses with greater than 0.25 diopter (built-in astigmatism), however, no lenses showed more than 0.5 diopter astigmatism. Two lenses had a built-in double image, another clinically significant problem. We believe the optical quality of the lenses from some lens manufacturers cannot be guaranteed.