Application of hydrogel lens average thickness

The equation for the average thickness of a hydrogel lens is a complex function. This report gives a simple method of estimating this parameter. By structuring the information into nomograms, an accurate system is derived which facilitates the design of a contact lens to provide a required average oxygen transmissibility. Several examples of the accuracy of the estimated value compared to the calculated value are shown. Details of the use of these nomograms are given with a discussion on the worth of an average thickness value as compared to a local thickness value.