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: 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.