Optimum design of the hybrid (diffractive/refractive) multifocal intraocular lenses implanted within human eye

Abstract

The human eye natural crystalline lens becomes opaque due to cataract. For improvement of the eye vision, the crystalline lens is typically surgically removed and replaced by an intraocular lens (IOLs). The optimum design of hybrid multifocal intraocular lenses (MIOLs) implanted within the human eye model is proposed. The AR40N acrylic MIOLs material has good biocompatibility. Two types of hybrid MIOLs (diffractive/refractive (D/R) and refractive/ diffractive (R/D)) with four foci were designed and evaluated. A comparison between the image quality for a healthy eye (Liou & Brennan model) and an eye with the implanted hybrid MIOLs has been performed based on ZEMAX-EE optical software. The image characteristics, point spread function (PSF), modulation transfer function (MTF), blur spot size, and longitudinal chromatic aberration (LCA) were used as an image criterion in this study. The eye pupil diameter was “3 mm,” the visual field of view was 5 degrees, and the light spectral region was 455- 655 nm. Results indicate that both hybrid MIOLs models achieved good visual acuity (sharp vision) for distances within the range 25 to 108 cm. The MIOLs made a remarkable correction in chromatic aberration than the healthy eye. The MTF for R/D-MIOL model improves the visual quality more than D/R-MIOL and healthy eye models.