GAS PERMEABLE HARD CONTACT LENS AND METHOD OF PRODUCING IT

• Main Authors: SHIRAFUJI, TOHRU, SHIMIZU, TERUHISA, YOKOYAMA, YUICHI, MITOMO, KIKUO, SUDA, HIDEO
• Format: Patent
• Language: English; French; Japanese
• Published: 18.11.1999
• Edition: 6
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; CHEMISTRY; COMPOSITIONS BASED THEREON; CONTACT LENSES; INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; OPTICS; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; PHYSICS; PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCESIN A PLASTIC STATE; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; SPECTACLES; SUNGLASSES OR GOGGLES INSOFAR AS THEY HAVE THE SAME FEATURESAS SPECTACLES; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

A method of producing a gas permeable hard contact lens, comprising rolling by heating a crosslinking gas permeable hard contact lens material and then machining the rolled material; and a gas permeable hard contact lens consisting of a crosslinking gas permeable hard contact lens material rolled by heating so as to provide a compressibility of 5 to 50 % and a compression bending fracture strength of 300 to 1500 g. The method can efficiently produce a gas permeable hard contact lens which is free from optical strain, excellent in transparency, small in internal stress, easy to mount and enhanced in endurance strength. Procédé servant à fabriquer une lentille de contact dure perméable aux gaz et consistant à laminer par réchauffement un matériau de réticulation devant constituer la lentille de contact dure, puis à usiner ledit matériau laminé. Lentille de contact dure perméable aux gaz constituée par un matériau de réticulation perméable aux gaz laminé par réchauffement, de sorte qu'il présente une compressibilité de 5 à 50 % et une résistance à la fracture provoquée par un cintrage par compression de 300 à 1500 g. Ce procédé permet de fabriquer de façon efficace une lentille de contact dure perméable aux gaz sans contrainte optique possédant une transparence excellente, une sollicitation interne limitée, ainsi que des caractéristiques de facilité de montage et de robustesse améliorée.