Contact lens and process for fitting
US6540353B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 16, 1998 |
| Grant date | Apr 1, 2003 |
| Priority date | — |
| Expiry date | Dec 16, 2018 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61F9/007
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
An aspheric multifocal contact lens for wearing by a patient with presbyopia is disclosed. The lens has a lens body with a rear surface adapted to fit on the surface of the eye and a front surface that interacts with the rear surface to bring about the desired optics of the lens. The lens also has a centrally located and generally circular first optic zone providing a first power correction for near vision, and a second optic zone concentric with the first optic zone and located peripherally therefrom providing a second power correction for distance vision. A transition zone concentric with the first optic zone is located between said first and second optic zones. The transition zone provides a rapid power shift of about 0.8 to about 1.6 diopters over a distance of about 0.25 mm between the power correction of the first and second zones.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.