Speaker
Description
Contact lenses are worn by millions of people worldwide to correct vision impairments. The mechanical interactions between the lens and the ocular surface are difficult to access in the clinic. We developed a mathematical model of the mechanical interactions between the lens and the eye to predict the ocular stress load due to contact lens wear.
The lens is modeled as a thin, axially symmetric, linear elastic material that conforms to the eye [1]. The eye is modeled as an axially symmetric, linear elastic material with spatially varying material properties. The eye and lens models are coupled non-linearly via the suction pressure under the lens [2]; we assume the thin tear film layer between the lens and the eye has a constant thickness. The coupled problem is solved by an iterative numerical algorithm using finite difference methods to approximate the lens mechanics and f inite element methods to approximate the eye. We have extended the model to account for the effect of intraocular pressure (IOP) on lens-eye interactions.
The model predicts that the center of the cornea (center of the eye) is negatively displaced (toward the inside of the eye), while the edge of the cornea is positively displaced and experiences the highest stresses. The final aim of this work is to improve contact lens design and the fitting process by predicting ocular deformations and ocular stress load before wearing a lens.
[1] Ross D.S., Maki K.L., Holz E.K., Existence theory for the radially symmetric contact lens equation, SIAM J. Appl. Math., Vol. 76(3), 827-844 (2016). https://doi.org/10.1137/15M1036865.
[2] Carichino L., Maki K.L., Ross D.S., Supple R.K., Rysdam E., Quantifying Ocular Surface Changes with Contact Lens Wear, Mathematical Biosciences and Engineering, Vol. 23(1), 172209 (2026). https://doi.org/10.3934/mbe.2026008.
