US5020898A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Contact lens for correction of astigmatism
Assignee: WJ ACQUISITION CORP
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Filing: 1990-01-29
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Granted: 1991-06-04
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Expires: 2010-01-29
Abstract
Abstract A contact lens for correcting astigmatism. The front surface has a central optical zone and an outer carrier having two points of maximum thickness located at an oblique angle of about 110° to 130° as measured from the vertical axis of the lens. The anterior surface of the lens is symmetrical about its vertical axis. The carrier tapers from the points of maximum thickness to thin portions at the top and bottom of the lens. The rear surface of the lens has an outer spherical base curve zone, an inner toric zone, and an intermediate transition zone having thickness that gradually increase from the base curve zone to the toric zone. By making the radius of the base curve zone substantially equal to that of the toric zone's major meridian, a thinner, more comfortable lens is obtained.
Inventors
- 👤 Malcolm Townsley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:27
CPC Classifications
G; G02; G02C; G02C7/00; G02C7/02; G02C7/04; G02C7/048
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
145 words
A contact lens of general concavo-convex configuration having improved rotational stability and rotational orientation wherein the anterior surface of said lens comprises a central optical zone and an outer carrier having a generally tapered surface with a thin portion at the upper edge of the lens and two points of maximum thickness located at oblique angles, α, of about 110° to about 130° as measured from the vertical axis from the top of the lens; the anterior surface of said lens being symmetrical about the vertical axis, the carrier tapering from the points of maximum thickness to a thin portion located at the top of the lens and a thin portion located at the lower edge of the lens in a smooth curve and the carrier tapering in a smooth curve along the vertical axis from the optical zone to the bottom of the lens.
Claim 2
Dependent Claim
145 words
A contact lens of general concavo-convex configuration having improved rotational stability and rotational orientation wherein the anterior surface of said lens comprises a central optical zone and an outer carrier having a generally tapered surface with a thin portion at the upper edge of the lens and two points of maximum thickness located at oblique angles, α, of about 110° to about 130° as measured from the vertical axis from the top of the lens; the anterior surface of said lens being symmetrical about the vertical axis, the carrier tapering from the points of maximum thickness to a thin portion located at the top of the lens and a thin portion located at the lower edge of the lens in a smooth curve and the carrier tapering in a smooth curve along the vertical axis from the optical zone to the bottom of the lens.
Claim 3
Dependent Claim
32 words
The contact lens according to claim 1 wherein the maximum thickness of the lens is located on radii at points about 0.7 to about 1.5 mm from the edge of the lens.
Claim 4
Dependent Claim
19 words
The contact lens according to claim 1 or 2 wherein the angle, α, is about 115° to about 125°.
Claim 5
Dependent Claim
13 words
The contact lens according to claim 3 wherein the angle, α, is 120°.
Claim 6
Dependent Claim
22 words
The contact lens according to claim 1 or 2 wherein the anterior surface of the lens is provided with a concentric trim.
Claim 7
Dependent Claim
17 words
The contact lens according to claim 3 wherein the anterior surface is provided with a concentric trim.
Claim 8
Dependent Claim
17 words
The contact lens according to claims 4 wherein the anterior surface is provided with a concentric trim.
Claim 9
Dependent Claim
148 words
A contact lens for correcting astigmatism of general concavo-convex configuration having a posterior surface comprising: (a) an outer annular spherical base curve zone; (b) an inner toric zone having a major meridian and a minor meridian orthagonal to each other; and (c) transition zone between the toric zone and the base curve zone having thickness that gradually increases from the base curve zone to the toric zone; wherein the radius of the base curve zone is substantially equal to the radius of the major meridian; the intersection of the minor meridian and the transition zone is located no more than 0.12 mm below an imaginary extension of the spherical base curve zone passing above that intersection; and the intersection of the major meridian and the transition zone is located no more than 0.07 mm below an imaginary extension of the spherical base curve zone passing above that intersection.
Claim 10
Dependent Claim
148 words
A contact lens for correcting astigmatism of general concavo-convex configuration having a posterior surface comprising: (a) an outer annular spherical base curve zone; (b) an inner toric zone having a major meridian and a minor meridian orthagonal to each other; and (c) transition zone between the toric zone and the base curve zone having thickness that gradually increases from the base curve zone to the toric zone; wherein the radius of the base curve zone is substantially equal to the radius of the major meridian; the intersection of the minor meridian and the transition zone is located no more than 0.12 mm below an imaginary extension of the spherical base curve zone passing above that intersection; and the intersection of the major meridian and the transition zone is located no more than 0.07 mm below an imaginary extension of the spherical base curve zone passing above that intersection.
Claim 11
Dependent Claim
36 words
A contact lens in accordance with claim 8 wherein the intersection of the minor meridian and the transition zone is located from 0.04 to 0.12 mm below an imaginary extension of the spherical base curve zone.
Claim 12
Dependent Claim
107 words
The lens of claim 8 wherein the anterior surface comprises a central optical zone and an outer carrier having a generally tapered surface with a thin portion at the upper edge of the lens and two points of maximum thickness located at an oblique angle α of about 110° to about 130° as measured from the vertical axis of the lens, said anterior surface being symmetrical about its vertical axis, the carrier tapering from the points of maximum thickness to a thin portion located at the top of the lens and to a thin portion located at the lower edge of the lens in a smooth curve.
Claim 13
Dependent Claim
30 words
The contact lens of claim 10 wherein the maximum thickness of the lens is located on radii at points about 0.7 to 1.5 mm from the edge of the lens.
Claim 14
Dependent Claim
14 words
The lens of claim 10 wherein the angle α is about 115° to 125°.
Claim 15
Dependent Claim
12 words
The lens of claim 12 wherein the angle α is about 120°.
Claim 16
Dependent Claim
13 words
The lens of claim 10 wherein the anterior surface has a concentric trim.
Claim 17
Dependent Claim
13 words
The lens of claim 11 wherein the anterior surface has a concentric trim.
Claim 18
Dependent Claim
43 words
The lens of claim 10 wherein the angle α is measured from the vertical axis from the top of the lens and the carrier tapers in a smooth curve along the vertical axis from the optical zone to the bottom of the lens.
Claim 19
Dependent Claim
30 words
The contact lens of claim 16 wherein the maximum thickness of the lens is located on radii at points about 0.7 to 0.15 mm from the edge of the lens.
Claim 20
Dependent Claim
14 words
The lens of claim 16 wherein the angle α is about 115° to 125°.
Claim 21
Dependent Claim
12 words
The lens of claim 18 wherein the angle α is about 120°.
Claim 22
Dependent Claim
13 words
The lens of claim 16 wherein the anterior surface has a concentric trim.
Claim 23
Dependent Claim
13 words
The lens of claim 17 wherein the anterior surface has a concentric trim.
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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) | 1994-06-03 | 1994-12-03 | 1995-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-06-03 | 1998-12-03 | 1999-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-06-03 | 2002-12-03 | 2003-06-04 | $7700.00 | Window Closed / Lapsed |