Multifocal contact lens
US5619289A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 16, 1994 |
| Grant date | Apr 8, 1997 |
| Priority date | — |
| Expiry date | Sep 16, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02C7/043
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A multifocal contact lens customized for a patient has, in accordance with the present invention, an anterior side with a power curve defined in part by a (i) central aspheric surface, (ii) an inner annular surface contiguous with the central aspheric surface, (iii) a second annular surface contiguous along a radially inner periphery with the inner annular aspheric surface, and (iv) an outer annular surface contiguous along a radially inner periphery with the second annular aspheric surface. Each of the annular surfaces is concentric or coaxial with the central aspheric surface. The central aspheric surface corresponds to a distance vision correction zone. The inner annular surface is an aspheric surface corresponding to a progressive add zone with a standard eccentricity between approximately -1.5 and approximately -5.0. The second annular surface corresponds to a near vision correction zone, and the outer annular surface corresponds to a distant vision correction zone.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.