Multifocal ophthalmic lens
US6540354B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 2, 1999 |
| Grant date | Apr 1, 2003 |
| Priority date | — |
| Expiry date | Sep 2, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02C7/061
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A multifocal ophthalmic lens comprising a far vision region, a near vision region an intermediate vision region and a main meridian of progression passing through these three regions is provided in which a principal length of progression, defined as a ratio between power addition and maximum slope of mean sphere along the meridian is less than 16 mm, sphere varies in a monotonous fashion as a function of angle on a 20 mm radius circle centered on a geometric center of the lens at both sides of said meridian, and in which the far vision region includes an angular sector having its origin at the geometric center of the lens with an included angle greater than 150°. This provides a good distribution of isocylinder and ionosphere lines over the lens, ensuring progression is very gentle.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.