Intraocular multifocal lens
US4917681A · kind A · utility
Inventor
Key dates
| Filing date | Aug 15, 1988 |
| Grant date | Apr 17, 1990 |
| Priority date | — |
| Expiry date | Aug 15, 2008 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61F2/1618
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
An intraocular lens, in form of a disk, intended to replace the crystalline lens of a patient's eye, in particular after a cataract extraction, comprises on its distal side an aspherical sector extending approximately from the midline of the disk over one quarter of the surface thereof. The rest of the distal side is spherical. The radius of curvature of the aspherical sector varies monotonously between the value of the radius of the spherical sectors and a lower value. Such a configuration allows light rays impinging on the intraocular lens to be refracted at different angles and provides both near the distance vision. The discontinuity at transition between the aspherical sector and the spherical sector is blocked out by dark or etched plastic to eliminate glare. The proximal side can either be a convex surface, a concave surface or a plane.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.