Multifocal corneal contact lens
US5898473A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 25, 1997 |
| Grant date | Apr 27, 1999 |
| Priority date | — |
| Expiry date | Apr 25, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02C7/042
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A pair of multifocal contact lenses for a patient comprises a first corneal contact lens having a concave posterior surface and a convex anterior surface. The anterior surface is formed with a power curve having exactly two vision correction zones, namely, a circular distance vision correction zone and an annular intermediate vision correction zone contiguous with the distance vision correction zone. The intermediate vision correction zone of the first lens is concentric or coaxial with the distance vision correction zone. A second corneal contact lens of the pair also has a concave posterior surface and a convex anterior surface. The anterior surface of the second lens is formed with a power curve having exactly two vision correction zones: a circular near vision correction zone and an annular intermediate vision correction zone contiguous with the near vision correction zone. The intermediate vision correction zone of the second lens is concentric or coaxial with the near vision correction zone. The intermediate vision correction zone of the first lens and the distance vision correction zone have optical powers differing in magnitude by less than approximately 1.5 diopters. Simil…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.