Fabrication of soft plastic contact lens blank and composition therefor

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, SOILD, SHAPED MASSES WHICH MAY BE CUT IN THE DRY STATE, AFTER STEP (1), 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 ELASTICALLY AND ITS ELASTIC RECOVERY AND IMPROVE ITS DIMENSIONAL STABILTIY. FROM 2045% BY WEIGHT OF POLYVINYL PYRROLIDONE IMPARTS HYGROSCOPIC AND UNUSUAL WATER-SWELLING CHARACTERISTICS. THE WATER SWOLLEN LENS CONTAINS FROM 40, 80% WATER PREFERABLY FROM 50-55%, AND IN ISOTONIC SALINE, THE WATER CONTENT CHANGES TO ABOUT 52-58%. AS A RESULT OF THE POLY- VINYL 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

• 👤 Driscoll K O
• 👤 A Isen

Bibliographic Details