Effects of contact lens deformation on tear film pressures induced during blinking.

The pressures induced in a tear film between a contact lens and the eye during the initial stages of a blink are estimated by means of a flexible slider-bearing model. Calculations are made of the pressure distributions as functions of two nondimensional parameters, one of which is purely geometrical and the other involves the sliding velocity, the viscosity of the tear film, and the flexibility of the lens. For the dimensions and velocities which apply to a typical blink, it is found that the effects of soft lens deformation in reducing pressure can be significant, especially for small tear film thicknesses.