Progressive multifocal ophthalmic lens
US4778266A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 8, 1986 |
| Grant date | Oct 18, 1988 |
| Priority date | — |
| Expiry date | Oct 8, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02C7/061
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A progressive multifocal ophthalmic lens has a main meridian along at least part of which the curvature of the lens varies continuously. On each side of the main meridian the areas of aberration are symmetrical to each other. The main meridian intersects a horizontal plane through the optical center of the lens at a point which, relative to a vertical plane passing through the optical center, is spherically offset towards the nose. This offset is between 0.8 and 1.33 millimeters. The plane containing the main meridian is at an angle between 5.5 degrees and 7.5 degrees to the vertical plane. The main meridian converges towards the nose in the lower part of the lens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.