Multifocal lens designs with intermediate optical powers
US5682223A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 4, 1995 |
| Grant date | Oct 28, 1997 |
| Priority date | — |
| Expiry date | May 4, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02C7/06
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A multifocus, concentric annular ring lens wherein one of the front and back surfaces of the lens defines a central area comprising a circular disc having a spherical surface corresponding to a basic prescription Rx spherical distance optical power. A plurality of annular rings surround the central area and have alternating spherical near and distance optical powers, and at least one intermediate optical power annular ring. The immediate optical power annular ring is located in the middle or outer region of the lens optic zone, and its optical power is intermediate to the distance and near optical powers, to provide visual acuity at intermediate distances. The intermediate optical power annular ring can be placed anywhere in the middle or outer region of the lens optic zone, and can be the second annular ring from the outer edge of the lens optic zone, or can be the outermost annular ring which defines the outer circumference of the lens optic zone. The lens can be a contact lens to be worn on the cornea of the eye, such as a soft hydrogel contact lens, or can be an intraocular lens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.