Patent ID: 6030077
Filing Date: 2000-02-29
Classification: A61F,G02C

Abstract:
A multifocal ocular lens having a vision correction area consisting of a plurality of vision correction regions having respective different values of an optical power, said plurality of vision correction regions including a central vision correction region, an outer vision correction region, and an intermediate region located between said central and outer vision correction regions, said vision correction area having an optical axis with which centers of said central and outer vision correction regions are aligned, said intermediate region consisting of a radially inner transition section adjacent to said central vision correction region and a radially outer transition section adjacent to said outer vision correction region,said central and outer vision correction regions having respectively determined first and second mutually different values (Pa, Pc) of said optical power, said optical power of said intermediate region changing from said first value to said second value, such that a rate of change of said optical power of said radially inner transition section increases with an increase in a radial distance from said optical axis of said vision correction area of said lens, along a first quadratic curve, while a rate of change of said optical power of said radially outer transition section increases with an increase in a radial distance from a radially inner periphery of said outer vision correction region, along a second quadratic curve,said first and second quadratic curves being connected to each other at a point of inflection which corresponds to a radial position of a boundary between said radially inner and outer transition sections, and which corresponds to a desired third value (Pb) of said optical power between said first and second values.