Multifocal optical lens
Abstract
Abstract A multifocal lens suitable for use as a contact lens or an intraocular lens which comprises at least 3 zones, the first zone comprising a polymer of a specified refractive index, the second zone comprising a polymer having the same repeating units as the polymer comprising the first zone and having a specified refractive index differing from the refractive index of the polymer comprising the first zone by not more than 0.1 units and by not less than 0.01 units and the third zone between the first and second zones comprising a polymer having the same repeating units as the polymer comprising the first and second zones and having a refractive index continuously variable between that of the polymer comprising the first zone and that of the polymer comprising the second zone, the at least three zones being transparent and having no discontinuities visible to the human eye between the zones.
Inventors
- 👤 Amitava Gupta
Bibliographic Details
Claims Analysis
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-10-30 | 1999-05-01 | 1999-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-10-30 | 2003-05-01 | 2003-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-10-30 | 2007-05-01 | 2007-10-31 | $7700.00 | Window Closed / Lapsed |