Author: Zoulinakis Georgios, University of Valencia
There are two different types of multifocal IOLs, the refractive and the diffractive ones. The first have zones (rings) of different refractive power while the second ones have a diffractive pattern on one of their surfaces. This diffractive pattern, according to its architecture, diffracts the light and focuses the light in more than one foci.
In order to design this type of lens in an optical design program we need to create this pattern on an IOL surface. For this, we developed a code in Matlab R2012b (The Mathworks, Inc.). With this code we can create the surface we want (Figure 1a) and control all the parameters like curvatures, asphericities, diffractive parameters etc. The code produces a text file of point coordinations that can be inserted into the software in order to be simulated and ray traced.
We have checked that the code creates correctly spherical/aspherical lenses that have same simulations as the ones from the software. After that we have been able to design diffractive IOLs (bifocal) which when simulated in the software.
Soon we will be able to advance it even more and produce a database of diffractive IOL simulations of different architectures.
Figure 1: Matlab images for apodization function, diffractive profile and IOL surface with diffractive pattern