Progressive addition lenses having regressive surfaces
US6139148A · kind A · utility
77Cited by
6References
17Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Feb 4, 1999 |
| Grant date | Oct 31, 2000 |
| Priority date | — |
| Expiry date | Feb 4, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02C7/063
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention provides progressive lenses with reduced unwanted astigmatism obtained by combining progressive addition and regressive surfaces. The unwanted astigmatisms of the progressive and regressive surfaces act to cancel each other. Thus, the lens has reduced unwanted astigmatism compared to prior art lenses of comparable dioptric add power.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.