Methods for designing and making contact lenses having aberration control and contact lenses made thereby
US6082856A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 9, 1998 |
| Grant date | Jul 4, 2000 |
| Priority date | — |
| Expiry date | Nov 9, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02C7/04
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method for constructing a soft contact lens having a prescribed power correction for focusing light on the retina of an eye is described. The method provides a soft contact lens that, when in place ("flexed") on the wearer's eye, is designed and manufactured to provide a substantially ellipsoidal anterior surface. In the method, an eye model including a cornea, a crystalline lens and a retina is constructed. Then a shape for an anterior surface of the cornea is selected to be a conic section having an eccentricity in the range of about 0.14<e<0.63. Next, a preliminary soft contact lens is selected having a center thickness, a radius, a posterior contact lens surface and an anterior contact lens surface to provide a prescribed plus or minus correction power such that, when applied to the anterior surface of the cornea, the anterior contact lens surface defining a conic section having a shape factor in the range of 0<E<1 or -1<E<0. An analysis is performed using the preliminary soft contact lens and eye model tracing light ray paths through the contact lens/eye system. The shape factor of the anterior contact lens surface when applied to the anterior surface of the cornea is varied…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.