Progressive spectacle lens
US5771089A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 16, 1997 |
| Grant date | Jun 23, 1998 |
| Priority date | — |
| Expiry date | May 16, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02C2202/16
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A progressive spectacle lens is described which has a convex aspherical front surface 1 and a concave aspherical back surface 2, of which at least one surface contributes to the power increase from the distance portion 3 over the progression corridor 4 to the reading portion 5. The progressive spectacle lens in accordance with the present invention is characterized by the fact that the surface 1 or the surfaces contributing to the power increase are designed in such a way that the main portion of astigmatism is transposed into an area 3 in which the power practically does not increase and by the fact that the surface astigmatism of the two surfaces 1 and 2 substantially cancel each other out in these areas 3 or 6. (See FIG. 1).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.