Model for representing an ophthalmic lens surface
US6789898B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 11, 2003 |
| Grant date | Sep 14, 2004 |
| Priority date | — |
| Expiry date | Jun 11, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02C7/063
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An ophthalmic lens having a complex surface and a toric or spherical surface is represented in a model using a prism reference point and a prescription point on the complex surface, the normal to the complex surface at the prism reference point, the local characteristics of the complex surface at the prescription point or around the prescription point, lens thickness measured along the axis defined by the normal to the complex surface, the plane tangential to the toric or spherical surface on the axis, and the curvatures of the toric or spherical surface. Representation of the lens in this model allows calculation of the toric or spherical surface without knowing all the characteristics of the complex surface. Calculations are simpler for the fitting of the lens into frames adapted to the wearer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.