Multi-focal diffractive ophthalmic lenses
US5129718A · kind A · utility
105Cited by
5References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 21, 1989 |
| Grant date | Jul 14, 1992 |
| Priority date | — |
| Expiry date | Nov 21, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02C2202/20
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An ophthalmic lens exhibiting diffractive power has a plurality of diffractive zones and smooth surfaces. The zones are arranged such that R.sub.0.sup.2 does not equal R.sub.1.sup.2 -R.sub.0.sup.2 where R.sub.0 is the radius of the central zone and R.sub.1 is the radius of the first annular zone.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.