Progressive lens elements and methods for designing and using same
US5861935A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 10, 1997 |
| Grant date | Jan 19, 1999 |
| Priority date | — |
| Expiry date | Jan 10, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02C2202/08
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A series of progressive ophthalmic lens elements, each lens element including a lens surface having PA1 an upper viewing zone having a surface power to achieve a refracting power corresponding to distance vision; PA1 a lower viewing zone having a greater surface power than the upper viewing zone to achieve a refracting power corresponding to near vision; PA1 a corridor of relatively low surface astigmatism connecting the upper and lower zones, said corridor having a surface power varying from that of the upper viewing zone to that of the lower viewing zone; the progressive ophthalmic tens series including PA1 a first set of lens elements having a base curve(s) suitable for use in providing a range of distance prescriptions for a first category of patient; and PA1 a second set of lens elements having a base curve(s) suitable for use in providing a range of distance prescriptions for a second category of patient; each lens element within a set differing in prescribed addition power and including a progressive design, in at least one of the upper and lower viewing zones, depending upon the addition power of the lens element; the lens elements in the first set differing substantively i…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.