Soft contact lens and method of manufacturing the same

• US 4,966,924 A
• Filed: 05/15/1989
• Issued: 10/30/1990
• Est. Priority Date: 02/13/1986
• Status: Expired due to Fees

• Current Assignee: Bio-Materials Univers Company
• Original Assignee: Bio-Materials Univers Company
• Inventors: Ikada, Yoshito, Hyon, Suong-Hyu
• Primary Examiner(s): Schofer, Joseph L.
• Assistant Examiner(s): REDDICK, MARIE L
• Application Number:
  US07/351,348
• Time in Patent Office: 533 Days
• Field of Search: 524/557, 525/61, 523/106
• US Class Current: 523/106
• CPC Class Codes: B29D 11/00076 enabling passage of fluids, e.g. oxygen, tears, between the area under the lens and the lens exterior
• CPC Class Codes: C08L 29/00 Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an alcohol, ether, aldehydo, ketonic, acetal or ketal radical; Compositions of hydrolysed polymers of esters of unsaturated alcohols with saturated carboxylic acids; Compositions of derivatives of such polymers
• CPC Class Codes: G02B 1/043 Contact lenses
• CPC Class Codes: G02C 7/04 Contact lenses for the eyes disinfection or sterilisation of contact lenses A61L12/00

Abstract

A soft contact lens of PVA having a tensile strength of not less than 10 kg/cm², a water content ranging from 40 to 95% by weight, a visible light transparency of not less than 90%, and an oxygen permeability of not less than 30×10^-11 cm³ ·(STP)·cm/cm² ·sec·mmHg. This soft contact lens can be prepared by forming a solution of PVA in a mixed solvent of water and an organic solvent, pouring the PVA solution in a mold having a shape of contact lens, and crystallizing at a temperature of not more than ordinary temperature. The soft contact lens has a high mechanical strength, high water content, high transparency and high oxygen permeability.

Claims

1. A soft contact lens of poly(vinyl alcohol), consisting essentially of microcrystalline poly(vinyl alcohol) crosslinked by irradiation with electron beams or radioactive rays, prepared by crystallizing a poly(vinyl alcohol) at a temperature of not more than 0°

C., and having a tensile strength greater than 10kg/cm², a water content ranging from 40 to 95% by weight, a visible light transparency of not less than 90%, and an oxygen permeability of not less than 30×

10^-11 cm ³ (STP) cm/cm² sec mmHg.

2. A soft contact lens according to claim 1, wherein the soft contact lens has pores with a pore size of 1 to 3 μ

m.

3. A soft contact lens according to claim 1, wherein the crystallized poly(vinyl alcohol) consists of microcrystalline poly(vinyl alcohol) crosslinked in a three-dimensional network.

4. A soft contact lens according to claim 1, wherein the microcrystalline poly(vinyl alcohol) is prepared by crystallizing poly(vinyl alcohol) from a solution having a mixed solvent comprising water and an organic solvent, at a temperature of not more than 0°

°

C.