Set of progressive multifocal ophthalmic lenses
US6318859A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 17, 1999 |
| Grant date | Nov 20, 2001 |
| Priority date | — |
| Expiry date | Jun 17, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02C2202/08
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention concerns a set of progressive multifocal opthalmic lenses, each having a first progressive multifocal surface and a second surface preferably spherical. It proposes to define the set of lenses with regard to the optical characteristics of the lenses, and particularly wearer power and oblique astigmatism, in worn conditions. For this purpose, the invention defines an ergorama associating with each sight direction in worn conditions a target object point, and a given power. This ergorama supplies a power target for a definition by optimisation of the lenses, and is used in a radii plotting programme for calculating the optical characteristics during optimisation. The set of lenses has substantially identical optical performances for a given addition, whatever the power of the far vision reference point.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.