Enhanced ophthalmic lens
US5867246A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 17, 1997 |
| Grant date | Feb 2, 1999 |
| Priority date | — |
| Expiry date | Jan 17, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02C7/061
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A progressive ophthalmic lens including a lens surface having: a lower viewing zone providing good optical quality at a predetermined high surface power over a large area of vision; said predetermined power being determined by the viewer's near prescription (R.sub.x) the horizontal fitting position normally being determined by the near pupillary distance of the wearer, and the vertical fitting position normally being determined by the vertical frame midpoint, an upper viewing zone of lower surface power providing an enhanced range of vision for intermediate or greater viewing distances; and a corridor of relatively low astigmatism extending therebetween; wherein the contours of mean surface power and/or surface astigmatism within the lower viewing zone, upper viewing zone and corridor are generally symmetric about a vertical lens meridian as fitted to the wearer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.