Abstract: A biological material is prepared for use in ophthalmology by steps of providing animal pericardium, subjecting the animal pericardium to multiple steps of freezing and thawing in a salt solution and incubating the animal pericardium in a solution of ammonia and ethyl alcohol. The multiple steps of freezing and thawing are conducted in a mixture of about 0.9% sodium chloride solution and distilled water in about 1:1 proportions of sodium chloride solution to distilled water. The incubating step is conducted in a mixture of 1% ammonia solution and 1% ethyl alcohol solution in about 1:1 proportions of ammonia solution to ethyl alcohol solution over a period of 48 to 72 hours.

Abstract: A biological material is prepared for use in ophthalmology by steps of providing animal pericardium, subjecting the animal pericardium to multiple steps of freezing and thawing in a salt solution and incubating the animal pericardium in a solution of ammonia and ethyl alcohol. The multiple steps of freezing and thawing are conducted in a mixture of about 0.9% sodium chloride solution and distilled water in about 1:1 proportions of sodium chloride solution to distilled water. The incubating step is conducted in a mixture of 1% ammonia solution and 1% ethyl alcohol solution in about 1:1 proportions of ammonia solution to ethyl alcohol solution over a period of 48 to 72 hours.

Abstract: A biological material is prepared for use in ophthalmology by steps of providing animal pericardium, subjecting the animal pericardium to multiple steps of freezing and thawing in a salt solution and incubating the animal pericardium in a solution of ammonia and ethyl alcohol. The multiple steps of freezing and thawing are conducted in a mixture of about 0.9% sodium chloride solution and distilled water in about 1:1 proportions of sodium chloride solution to distilled water. The incubating step is conducted in a mixture of 1% ammonia solution and 1% ethyl alcohol solution in about 1:1 proportions of ammonia solution to ethyl alcohol solution over a period of 48 to 72 hours.

Abstract: A collagen containing substrate comprising cattle basal membrane is conditioned by incubating the membranes in a mixture of pepsin, hyaluronidase and acetic acid and separating the collagen from the mixture. The mixture can include pepsin, hyaluronidase and a 0.5M solution of acetic acid in 1:1:10 proportions. The incubation is conducted for about 10 hours at about 45.degree. C. After incubation, collagen is separated from the mixture by centrifuging at a speed of 5000 to 30000 rpms for about 30 minutes. The collagen is mixed with polymerizable monomer and polymerized to form a gel that can be ground to form an intraocular or contact lens.

Abstract: The present invention is directed to a biocompatible polymeric material and methods of making prepared by forming a mixture of collagen, a water-soluble ethylenically unsaturated compound and a cross-linking agent at a temperature of 30.degree. C. to 42.degree. C.; adjusting the pH of the mixture to 3.2 to 5.0; and polymerizing the mixture. The resulting material is rinsed in a physiologic solution at a temperature of 25.degree. C. to 80.degree. C. The resulting polymeric material has a modules of elasticity in the range of 10 to 27.times.10.sup.5 N/m.sup.2. Mechanical strength of the polymeric material is 20 to 100 times greater than polymeric material prepared by known methods. The material is optically transparent and is characterized by 95% or more light transmission in the visible spectrum and by resolution of 200 lines per mm for a +20D intraocular lens. The material is characterized by low protein absorption of about 0.1.times.10.sup.-3 .mu.

Abstract: A collagen containing substrate comprising cattle basal membrane is conditioned by incubating the membranes in a mixture of pepsin, hyaluronidase and acetic acid and separating the collagen from the mixture. The mixture can include pepsin, hyaluronidase and a 0.5 M solution of acetic acid in 1:1:10 proportions. The incubation is conducted for about 10 hours at about 45.degree. C. After incubation, collagen is separated from the mixture by centrifuging at a speed of 5000 to 30000 rpms for about 30 minutes. The collagen is mixed with polymerizable monomer and polymerized to form a gel that can be ground to form an intraocular or contact lens.

Abstract: A collagen containing substrate comprising cattle basal membrane is conditioned by incubating the membranes in a mixture of pepsin, hyaluronidase and acetic acid and separating the collagen from the mixture. The mixture can include pepsin, hyaluronidase and a 0.5M solution of acetic acid in 1:1:10 proportions. The incubation is conducted for about 10 hours at about 45.degree. C. After incubation, collagen is separated from the mixture by centrifuging at a speed of 5000 to 30000 rpms for about 30 minutes. The collagen is mixed with polymerizable monomer and polymerized to form a gel that can be ground to form an intraocular or contact lens.

Abstract: The present intraocular lens includes a body portion and an optic portion. A thickness of the body portion is between 0.3 to 0.98% of a thickness of the intraocular lens itself which lens includes the body portion and the optic portion, and from 0.011 and 0.015% of a length of the body portion. The thickness of the intraocular lens itself, from 0.095 and 0.192% of the length of the body portion. The diameter of the optic portion is from 0.153 and 0.7% of the length of the body portion. The optic portion can have an anterior surface having a radius of curvature of from 0.29 and 0.967% of the radius of curvature of the posterior surface of said intraocular lens. The lens is implanted by insertion into the posterior chamber of the eye to a position anterior to the natural crystalline lens of the eye. The implanted lens is effective in correcting moderate to severe forms of hypermetropia.