New intraocular lens for achromatizing the human eye

PURPOSE: To describe the design of a new intraocular lens (IOL) capable of correcting spherical and chromatic aberrations when implanted in the human eye. SETTING: University of Murcia, Murcia, and University of Valencia, Valencia, Spain. METHODS: A hybrid singlet achromatic IOL was designed. The IOL has a combination of a refractive and a diffractive surface, with 1 of the surfaces being aspherical. Optical simulations were used to model the polychromatic modulation transfer function (MTF) in pseudophakic eyes to explain the differences in optical quality afforded by the achromatic IOL. Parameters such as focus shift, optical path difference, through-focus, and robustness to tilt and decentering of achromatic IOLs were obtained. RESULTS: The polychromatic MTF in an eye with a centered, not tilted achromatic IOL was near the diffraction-limited MTF. The focus shift change for the achromatic IOL through the visible spectrum was approximately 0.1 diopter. The polychromatic MTF in an eye with the achromatic IOL would be similar to that in an eye with a spherically centered IOL if the achromatic IOL were decentered 1.0 mm or tilted 4 degrees. The range of centration and tilt error for the achromatic IOL to obtain an optical benefit in the polychromatic MTF was larger than the typical postoperative IOL decentration and tilt errors. CONCLUSION: The hybrid singlet achromatic IOL design resolved the chromatic aberration problem, improving the overall optical quality in the human eye.