Differential thickness contact lens utilizing multiple base curves and method of manufacturing same
US5988813A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 21, 1998 |
| Grant date | Nov 23, 1999 |
| Priority date | — |
| Expiry date | Dec 21, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02C7/04
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method of producing a compensated contact lens that is compensated for power deviation from target due to differential shrinkage, and also a compensated contact lens. The invention includes the steps of designing a lens to have first and second areas of different thickness and a cylinder axis having a predetermined angular position; determining a plurality of power correction factors, one for each of a plurality of cylinder axis ranges of the lens; and modifying the lens using a selected one of the plurality of power correction factors corresponding to the cylinder axis ranges of the lens containing the cylinder axis of the lens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.