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The Story of Dr. Robert Morrison. Osprey, Fla.: SIS Publishing, 2006. [ S P E C I A L T H A N K S ]Special thanks to contributors Robert Davis, O.D.; Art Epstein, O.D.; and Glenda Secor, O.D., for their assistance with this series.1959 1960sWichterle and Lim publish a paper on hydrophilic gels A group of researchers at the University of California at Berkeley workedfor biological use. tirelessly in investigating the amount of oxygen needed by the cornea during contact lens wear.Key Developments in Contact Lens Materials And Design, 1975–2000BY JACK SCHAEFFER, O.D.AND JAN BEITING [ THE QUEST FOR OXYGEN ]By 1970, contact lens wear had become more practical and more comfortable than in previous decades, and as many as 2 million people worldwide were successfully wearing contact lenses.1For the next decade, Bausch & Lomb’s Soflens, the first hydrogel contact lens based on Otto Wichterle’s lens and the spincasting process by which it was made (also acquired from Wichterle), essentially dominated the marketplace. However, corneal hypoxia or oxygen deprivation of the cornea continued to be a serious impediment to safe and successful contact lens wear, even with the new soft hydrogel lenses just entering the market. As early as 1952, Edward Goodlaw, O.D., had suggestedthat contact lens wear could cause corneal edema. Further research proved that to be correct. The quest to deliver more oxygen to the cornea was on.Over the next three decades, the ranks of contact lens wearers would grow to more than 80 million, thanks in large part to the contributions of oxygenresearchers in academia and clinical practice.The Berkeley GroupFrom the mid-1960s through the mid-1980s, a group of researchers at the University of California at Berkeley worked tirelessly investigating the amount of oxygen needed by the cornea during contact lens wear and the effects of various types of contact lenses on oxygen transmission.Irving Fatt, Ph.D., F.A.A.O. (1920–1996), and Richard M. Hill, O.D., Ph.D., F.A.A.O., worked together at Berkeley to come up with a method for measuring how much oxygen penetrates a contact lens to reach the cornea. Dr. Fatt, whose expertise was in petroleum and bioengineering, took an engineering approach to the problem, measuring oxygen flux with electrodes. He realized that the same principles of fluid dynamics applied whether one was looking at petroleum, oxygen through plastic packaging or oxygen through a hydrogel device on the eye. He introduced the concepts of material permeability (Dk) and transmissibility (Dk/L) to the contact lens industry,2 and his research resulted in a universally recognized unit for oxygen permeability (the Fatt unit) that greatly advanced the science behind bothrigid gas permeable and hydrogel lenses.
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