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US3700761A Expired / Lapsed US ⏱️ 0.0 years remaining

Fabrication of soft plastic contact lens blank

Assignee: GRIFFIN LAB Inc
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Filing: 1969-11-28
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Granted: 1972-10-24
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Expires: 1989-11-28
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Abstract

Abstract Graft or block copolymers of hydroxy alkyl methacrylate esters and polyvinyl pyrrolidone are (1) cast in a shaping mold as a monomer-polymer dispersion, polymerized to a solid at 40*-60* C. in the presence of low and medium temperature free radical initiators, (2) the solid taken out of the mold and heated to 90*-120* C., and then post-polymerized by (3) radiation while dry and by (4) hydrogen peroxide treatment to form hygroscopic, solid, shaped masses which may be cut in the dry state, after step (2), into contact lenses. The lenses may be equilibrated in the wet state by hydrating with normal saline solution. The lenses may be maintained by treatment with hydrogen peroxide. Steps (3) and (4) toughen the lens, increase its elasticity and its elastic recovery and improve its dimensional stability. From 20 to 45 percent by weight of polyvinyl pyrrolidone imparts hygroscopic and unusual water-swelling characteristics while retaining elastic recovery. The water-swollen lens contains from 40-80 percent water, preferably from 50-55 percent, and in isotonic saline, the water content changes to about 52-58 percent. As a result of the polyvinyl pyrrolidone incorporation, the lens is readily cleaned after use in the eye with dilute hydrogen peroxide to rid it of imbibed muco-protein, catalase and the like.

Inventors

  • 👤 Kenneth F O'driscoll
  • 👤 Allan A Isen

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 06:41
CPC Classifications
G; G02; G02B; G02B1/00; G02B1/04; G02B1/041; G02B1/043; B; B29; B29D; B29D11/00; B29D11/00009; B29D11/00038; B29D11/00067; B29D11/00125; B29D11/00134; B29D11/00865; C; C08; C08F; C08F271/00; C08F271/02

Claims Analysis

Total Claims: 22
Claim 1
Independent Claim 32 words
casting said slurry in an open cylindrical mold and polymerizing at a temperature of 40*-60* C. to form a hard, self-supporting mass which is hygroscopic and swells anisotropically in a water medium;
Claim 2
Independent Claim 10 words
A method of shaping and cutting a contact lens comprising:
Claim 3
Dependent Claim 32 words
casting said slurry in an open cylindrical mold and polymerizing at a temperature of 40*-60* C. to form a hard, self-supporting mass which is hygroscopic and swells anisotropically in a water medium;
Claim 4
Dependent Claim 68 words
cutting away about 90-95 percent of the material from the planar face of the cylinder and from the circular outer periphery of the cylinder to leave the inner concave surface of the casting as the last surface to be cut as a lens blank having an arc of about 120* and in a diameter broad enough to cover the cornea and at least several millimeters of the limbus;
Claim 5
Dependent Claim 98 words
cutting a bevel edge at the periphery of the lens blank to form a lens having a semi-scleral flap which is adapted to be lifted up by tears in the scleral portion of the eye adjacent the outer edge of the flap while simultaneously forming a circular tear vesicle in the interior edge of the bevel which is spaced inwardly from said flap and which provides a circular well for tears in the eye at the limbal area, while the inner central portion of the lens is relatively flat to contact the cornea without any tear layer therebetween.
Claim 6
Dependent Claim 40 words
removing said mass and polymerizing at a temperature of 90*-120* C. to polymerize unreacted material from the polymerization with the first free radical initiator and to complete the hardening of said mass in its self-supporting condition outside of the mold;
Claim 7
Dependent Claim 41 words
removing said mass and polymerizing at a temperature of 90*-120* C. to polymerize unreacted material from the polymerization with the first free radical initiator and to complete the hardening of said mass in its self-supporting condition outside of the mold; and,
Claim 8
Independent Claim 8 words
The method of making a contact lens comprising:
Claim 9
Dependent Claim 6 words
cutting a lens from said mass;
Claim 10
Dependent Claim 6 words
cutting a lens from said mass;
Claim 11
Dependent Claim 32 words
subjecting said cut lens to polymerizing radiation for at least 5 minutes up to 4 hours to toughen said cut lens in both the dry state and when swollen with water; and
Claim 12
Dependent Claim 19 words
The method as claimed in claim 3, wherein the lens blank is irradiated prior to cutting the bevel edge.
Claim 13
Dependent Claim 21 words
The method as claimed in claim 3, wherein the lens is irradiated after cutting the bevel edge of the lens blank.
Claim 14
Dependent Claim 9 words
neutralizing and hydrating said cut lens in saline solution.
Claim 15
Dependent Claim 31 words
subjecting said cut mass to polymerizing radiation for at least 5 minutes up to 4 hours to toughen said cut mass in both the dry state and when swollen with water;
Claim 16
Dependent Claim 32 words
subjecting said cut mass to polymerizing radiation for at least 5 minutes up to 4 hours to toughen said cut mass in both the dry state and when swollen with water; and
Claim 17
Dependent Claim 9 words
neutralizing and hydrating said cut mass in saline solution.
Claim 18
Dependent Claim 10 words
neutralizing and hydrating said cut mass in saline solution; and,
Claim 19
Dependent Claim 42 words
The method as claimed in claim 3, wherein the center of the lens blank is cut and polished on both inner and outer surfaces to make its center thinner than the edges of the corneal section to thereby provide a minus correction.
Claim 20
Dependent Claim 28 words
The method as claimed in claim 3, wherein the lens blank is cut to make its corneal edges thinner than its center, to thereby provide a plus correction.
Claim 21
Dependent Claim 8 words
treating said cut mass with dilute hydrogen peroxide.
Claim 22
Dependent Claim 49 words
The method as claimed in claim 3, wherein the lens is cut and polished to be substantially the same thickness at its center and at its corneal edges, to thereby provide zero correction and produce a lens useful as a corneal bandage through which eye medicaments may be diffused.

References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1975-10-24 1976-04-24 1976-10-24 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1979-10-24 1980-04-24 1980-10-24 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1983-10-24 1984-04-24 1984-10-24 $7700.00 Window Closed / Lapsed

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