Hydrodynamics of a Soft Contact Lens During Sliding Motion

Abstract

Tear film thickness and pressure distribution under a tilting soft contact lens with peripheral slopes during the early stage of a blink are calculated for various flexibility and aspect ratios. The system is modeled as a slider bearing with the lens behaving as a deformable surface sliding over a rigid eye. The tear is considered to be a linearly viscous (Newtonian) fluid. The velocity profile at the edges and the junctions of the slopes are also calculated for a typical soft contact lens. Back flow at the edges is predicted. It is shown that the tilting of the lens has a major affect on the tendency of the pressure distribution. Also important is the lens’ flexibility for it influences both the film thickness and pressure distribution noticeably. [S0742-4787(00)01002-X]