Abstract
Purpose :
In this study we model and simulate the fluid and solid mechanics of a contact lens that has been displaced from its equilibrium position on the eye by a blink; lenses re-center themselves. This project is part of our ongoing enterprise of characterizing the mechanics of contact lenses and their effect on comfort and performance.
Methods :
We have built on our earlier work in which we devised a model of the suction pressure distribution in the post-lens tear film beneath a radially-symmetric contact lens. We have generalized that model to compute the suction pressure distribution under an arbitrarily-shaped lens on an arbitrarily-shaped eye. Variations in suction pressure drive the re-centering motion of the lens. We have devised a numerical algorithm that implements the model, and we have written a computer program that simulates the motion of a lens.
Results :
We probe how the different contact lens design parameters, such as shape, thickness, and material properties, influence the suction pressure distribution and thus the time and trajectory of the re-centering.We have found that thickness variations of the lens are particularly important.
Conclusions :
We developed a mathematical model of the re-centering dynamics of a contact lens in which suction pressure variations drive the motion of the lens. The partial differential equation captures the basic physics, the coupled elastic and fluid forces that re-center the lens.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.