Diffractive ophthalmic lens for correcting astigmatism
US5100226A · kind A · utility
84Cited by
4References
19Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Dec 19, 1989 |
| Grant date | Mar 31, 1992 |
| Priority date | — |
| Expiry date | Dec 19, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02C2202/20
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An artificial eye lens such as a contact lens or intra-ocular lens corrects astigmatism by two sets of substantially linear parallel zones arranged to diffract light predominantly into one order at one orientation, the spacing of the zones diminishing on either side of the linear axis. In addition circular diffraction zones may be provided to give both spherical and cylindrical power for astigmatism correction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.