Oxygen permeability of rigid contact lens materials

Abstract

The oxygen permeability of 28 currently available rigid contact lens materials was measured using the polarographic method, and the data were corrected for boundary and edge effects. Comparison of the measured oxygen permeability values with data supplied by manufacturers (nominal data) reveals a large discrepancy, whereby the measured values are less than the quoted values. This may be attributed to either (a) the manufacturers citing values derived from techniques other than the polarographic method (such as the coulometric technique), or (b) the manufacturers citing values derived earlier that have not been corrected for the edge or boundary effects. Practitioners should continue to exercise caution when interpreting oxygen transmissibility data.