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]

Issue Section:
Technical Papers
Keywords:
contact lenses, hydrodynamics, sliding friction, pressure, eye, viscosity, films
Topics:
Lenses (Optics), Pressure, Film thickness, Flow (Dynamics)
1.
Hayashi, T. T., 1977, “Mechanics of Contact Lens Motion,” Ph.D. thesis, University of California, Berkley.
2.
Mandell, R. B. 1974, Contact Lens Practice, Charles C. Thomas Publishers, Springfield, IL.
3.
Conway
,
H. D.
, and
Richman
,
M.
,
1982
, “
Effects of Contact Lens Deformation of Tear Film Pressures Induced During Blinking
,”
Am. J. Optom. Physiol. Opt.
,
59
, No.
1
, pp.
1
–
20
.
Copyright © 2000
 by ASME
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