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A REVIEW OF THE THEORETICAL CONCEPTS, MEASUREMENT SYSTEMS AND APPLICATION OF CONTACT LENS OXYGEN PERMEABILITY
Author(s) -
Brennan Noel A.,
Efron Nathan,
Holden Brien A.,
Fatt Irving
Publication year - 1987
Publication title -
ophthalmic and physiological optics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.147
H-Index - 66
eISSN - 1475-1313
pISSN - 0275-5408
DOI - 10.1111/j.1475-1313.1987.tb00783.x
Subject(s) - oxygen permeability , contact lens , permeability (electromagnetism) , standardization , lens (geology) , materials science , optics , oxygen , computer science , chemistry , physics , membrane , biochemistry , organic chemistry , operating system
— The interest in rigid gas‐permeable contact lenses for extended wear has prompted a re‐evaluation of the theoretical and practical aspects of the oxygen transport characteristics of contact lens materials. Oxygen permeability has been considered by some authors to be a parameter which is dependent upon the measurement conditions; however, this paper demonstrates that an intrinsic permeability coefficient may be derived for a given material when the basic principles of the transport mechanisms are considered. Two basic methodologies have been described for measuring oxygen permeability—dual‐chamber and electrochemical methods, the latter being the more popular. Although consistency in measured oxygen transmissibility of a given lens may be achieved among laboratories, current analytical techniques do not allow the intrinsic permeability coefficient of materials to be determined. Future research should be directed towards developing methods to fully correct for surface and edge effects, and to achieve standardization among laboratories.