US4318595A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Contact lens and method of making the same
Assignee: HIRST CONTACT LENS Ltd A CORP OF NEW ZEALAND
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Filing: 1979-08-28
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Granted: 1982-03-09
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Expires: 1999-08-28
Abstract
Abstract A contact lens, particularly a high minus power anterior surface toric lens, is made having a toric central optical portion without prism and an annular outer portion having prism but without toric effect, the outer portion being truncated in a lower part so that there is upward movement of the center of rotation of the blank and of the center of gravity in a manner such that the center of gravity is in use below the center of rotation, thus assisting if the lens is rotated by lid or eye movement the lens tends to rotate back into correct orientation.
Inventors
- 👤 Herbert C. Van der Kolk
- 👤 Martyn W. Davy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 02:26
CPC Classifications
G; G02; G02C; G02C7/00; G02C7/02; G02C7/04; G02C7/048
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
75 words
A method of manufacturing a contact lens having a lenticular anterior surface with a restricted central zone and a surrounding annular carrier comprising the steps of forming a toric anterior surface over said restricted central zone of the lens and forming an independent prism part of the lens over the carrier only of the lenticular anterior surface so that in use the center of gravity of the lens is below the center of rotation thereof.
Claim 2
Independent Claim
75 words
A method of manufacturing a contact lens having a lenticular anterior surface with a restricted central zone and a surrounding annular carrier comprising the steps of forming a toric anterior surface over said restricted central zone of the lens and forming an independent prism part of the lens over the carrier only of the lenticular anterior surface so that in use the center of gravity of the lens is below the center of rotation thereof.
Claim 3
Dependent Claim
42 words
A method as claimed in claim 1 which includes the step of truncating the annular carrier in the thicker lower area of the lens so that there is an upward movement of the center of gravity and of the center of rotation.
Claim 4
Dependent Claim
24 words
A method as claimed in claim 1 or claim 6 as applied to the production of a minus power anterior surface toroidal soft lens.
Claim 5
Dependent Claim
17 words
A method as claimed in claim 3 as applied to a contact lens having high minus power.
Claim 6
Dependent Claim
63 words
A contact lens comprising a lenticular anterior surface, a restricted central zone and a surrounding annular carrier, a toric anterior surface over said restricted central zone of the lens and an independent prims part of the lens over the carrier only of said lenticular anterior surface so that in use the center of gravity of the lens is below the center of rotation.
Claim 7
Dependent Claim
63 words
A contact lens comprising a lenticular anterior surface, a restricted central zone and a surrounding annular carrier, a toric anterior surface over said restricted central zone of the lens and an independent prims part of the lens over the carrier only of said lenticular anterior surface so that in use the center of gravity of the lens is below the center of rotation.
Claim 8
Dependent Claim
19 words
A contact lens as claimed in claim 5 wherein the lower portion of said carrier is thicker and truncated.
Claim 9
Dependent Claim
30 words
A contact lens as claimed in claim 5 or claim 6 wherein said toric part of said lens is restricted to a central area of about 81/2 mm in diameter.
Claim 10
Dependent Claim
25 words
A contact lens as claimed in either one of claims 5 or 6 wherein the lens is a minus power anterior surface toroidal soft lens.
Claim 11
Dependent Claim
15 words
A contact lens as claimed in claim 8 wherein the lens is high minus power.
References Cited (Backward Citations)
US3698802A
Cited
FR2281584A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-03-08 | 1985-09-07 | 1986-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-03-08 | 1989-09-07 | 1990-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-03-08 | 1993-09-07 | 1994-03-09 | $7700.00 | Window Closed / Lapsed |