Multifocal ocular lens having intermediate region with continuously varying optical power

Abstract From the Canadian patent

A multifocal ocular lens having a vision correction area which consists of a central an intermediate, and an outer vision correction region having respective different values of an optical power and which has an optical axis with which centers of the central and outer vision correction regions are aligned the central and outer vision correction regions having respectively determined first and second mutually different values of the optical power wherein the optical power of the intermediate region is represented by a combination of a first and a second quadratic curve connected to each other at a point of inflection which corresponds to a radial position of a boundary between the inner and …