ABSTRACT A method of predicting the oxygen tension distribution under a contact lens is illustrated for some simple, but practical, lens motions. A hydrodynamic theory is used to find those regions which receive fresh tear fluid during a blink. Then a diffusion model is solved to find the oxygen tension distribution at all times between blinks. The results are compared with earlier models in which details of the fluid flow were neglected, as were variations of oxygen tension with position under the lens. Depending on the motion of the lens, the tear fluid exchange factor can be quite large without eliminating regions in which the oxygen tension is below critical levels. The results suggest that the situation can be improved if the lens is designed for large displacements, with the blink, in the direction parallel to the cornea.
Robert E. Berger (Mon,) studied this question.