Silver mean sequence in extended depth of focus intraocular lenses: a comparative study of kinoform and stepwise designs

In this work, we present two new multifocal intraocular lens (MIOL) designs, both based on the silver mean kinoform diffractive lens. We demonstrate that a single aperiodic diffractive profile can be used to create two different MIOLs: one with a kinoform structure and the other with a stepwise profile. Quantitative assessment of the designs was carried out using the through focus modulation transfer function and the area under the modulation transfer function for the prediction of their visual performance. Our results show that both designs exhibit nearly identical optical performance at the design wavelength (λ = 550 nm), though their intrinsic longitudinal chromatic aberration differs significantly. Given that diffractive extended depth of focus (EDoF) intraocular lenses are prone to image degradation due to dysphotopic phenomena, we also compared the halos generated by these two designs and found notable differences in their behavior. Furthermore, under photopic conditions, the proposed lens designs demonstrated the potential to achieve visual acuity values of 0.2 logMAR or better across a vergence range from approximately 0 to 2 D. Finally, to qualitatively assess the behavior of the MIOLs, an objective experimental evaluation was conducted using an adaptive optics visual simulator in a model eye. Experimental results align with the quantitative assessment of the proposed designs.