Patent US4854089A successfully refreshed from Google Patents.
US4854089A
Expired / Lapsed
US
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Method of making a rigid gas permeable bifocal contact lens
Assignee: Novartis AG
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Filing: 1988-03-16
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Granted: 1989-08-08
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Expires: 2008-03-16
Abstract
Abstract A bifocal contact lens is disclosed, having a posterior surface with a base curve, and an anterior surface having a distance vision curve defining a distance vision optical zone and a near vision curve defining a near vision optical zone. A first prism component is incorporated into the base curve. A second prism component is incorporated into the distance vision curve. A process for manufacturing the bifocal contact lens by lathe cutting is also disclosed.
Inventors
- 👤 Heriberto Morales
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:54
CPC Classifications
G; G02; G02C; G02C7/00; G02C7/02; G02C7/04; G02C7/048; G02C7/041; Y; Y10; Y10T; Y10T409/00; Y10T409/30; Y10T409/303752; Y10T82/00; Y10T82/10
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
291 words
A method for making a bifocal contact lens from a polymer button having an anterior surface, a posterior surface, a circumferential edge, and a geometric center defined by the intersection of a horizontal axis and a vertical axis, said axes being parallel to the planes of said anterior and posterior surfaces, said method comprising the steps of: (a) rotating the button about a first axis of rotation, said first axis being perpendicular to the intersection of said horizontal and vertical axes and offset from said geometric center along said vertical axis; (b) forming a base curve in said posterior surface, said base curve being defined as a continuous arc centered about a point selected along said first axis of rotation; (c) rotating the button about a second axis of rotation, said second axis being parallel to said first axis and passing through said geometric center; (d) forming a near vision optical zone on said anterior surface, said near vision optical zone being defined as a continuous arc centered about a second point selected along said second axis of rotation, said near vision optical zone being restricted over a predetermined area of said anterior surface; (e) covering the anterior surface with a protective coating; (f) rotating the button about a third axis of rotation, said third axis being parallel to said first and second axes and offset from said geometric center along said vertical axis in a direction opposite of said first axis; and (g) forming a distance vision optical zone on said anterior surface, said distance vision optical zone being defined as a continuous arc centered about a point selected along said third axis of rotation, said distance vision optical zone being restricted over a predetermined area of said anterior surface.
Claim 2
Independent Claim
291 words
A method for making a bifocal contact lens from a polymer button having an anterior surface, a posterior surface, a circumferential edge, and a geometric center defined by the intersection of a horizontal axis and a vertical axis, said axes being parallel to the planes of said anterior and posterior surfaces, said method comprising the steps of: (a) rotating the button about a first axis of rotation, said first axis being perpendicular to the intersection of said horizontal and vertical axes and offset from said geometric center along said vertical axis; (b) forming a base curve in said posterior surface, said base curve being defined as a continuous arc centered about a point selected along said first axis of rotation; (c) rotating the button about a second axis of rotation, said second axis being parallel to said first axis and passing through said geometric center; (d) forming a near vision optical zone on said anterior surface, said near vision optical zone being defined as a continuous arc centered about a second point selected along said second axis of rotation, said near vision optical zone being restricted over a predetermined area of said anterior surface; (e) covering the anterior surface with a protective coating; (f) rotating the button about a third axis of rotation, said third axis being parallel to said first and second axes and offset from said geometric center along said vertical axis in a direction opposite of said first axis; and (g) forming a distance vision optical zone on said anterior surface, said distance vision optical zone being defined as a continuous arc centered about a point selected along said third axis of rotation, said distance vision optical zone being restricted over a predetermined area of said anterior surface.
Claim 3
Dependent Claim
68 words
The method of claim 1 wherein said distance vision optical zone is formed by moving a rotary cutting instrument gradually along the vertical axis from an apex end of said button towards a ballast end of said button, stopping at a apredetermined point slightly below the original geometric center of the button, thereby defining the near vision optical segment as being crescent shaped and having an up-curved boundary.
Claim 4
Dependent Claim
20 words
The method of claim 1 wherein said first axis of rotation is offset about 0.0075 inches from said geometric center.
Claim 5
Dependent Claim
27 words
The method of claim 1 comprising the additional step of removing a portion of the ballast of the lens before said final cleaning, polishing and inspecting step.
Claim 6
Dependent Claim
38 words
The method of claim 1 comprising the additional step of forming a lenticular zone on said anterior surface, said lenticular zone being defined as a continuous arc centered about a point selected along said second axis of rotation.
Claim 7
Dependent Claim
124 words
The method of claim 1 comprising the additional steps of: (h) rotating the button about said second axis of rotation; (i) removing an annular segment of the button until a desired lens diameter remains; (j) rotating the button about said first axis of rotation; (k) forming a secondary curve on said posterior surface surrounding said base curve, said secondary curve being defined as a continuous arc centered about a second point selected along said first axis of rotation; (l) forming a peripheral curve on said posterior surface surrounding said secondary curve, said peripheral curve being defined as a continuous arc centered about a third point selected along said first axis of rotation; (m) edging the lens; and (n) cleaning, polishing and inspecting the lens.
Claim 8
Dependent Claim
38 words
The method of claim 6 comprising the additional step of forming a lenticular zone on said anterior surface, said lenticular zone being defined as a continuous arc centered about a point selected along said second axis of rotation.
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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) | 1992-08-07 | 1993-02-06 | 1993-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-07 | 1997-02-06 | 1997-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-07 | 2001-02-06 | 2001-08-08 | $7700.00 | Window Closed / Lapsed |