Progressive multifocal ophthalmic lens
US5488442A · kind A · utility
48Cited by
3References
15Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 18, 1993 |
| Grant date | Jan 30, 1996 |
| Priority date | — |
| Expiry date | Nov 18, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02C7/061
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A progressive multifocal ophthalmic lens is provided having an aspherical surface comprising a distance vision portion, a near vision portion and an intermediate vision portion, in which the maximum mean sphere gradient value is situated in the intermediate vision portion of the principal meridian of progression of the lens, and the cylinder gradient over the whole aspherical surface of the lens is less than the product obtained by multiplying the power addition value at each point by a constant value coefficient.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.