A 'minimum-wear-and-tear' meshwork for the iris.

Large changes in pupil size occur frequently, yet the connective tissue components of the iris, consisting largely of relatively-inextensible collagen, last for many years. The concept of a minimum-wear-and-tear meshwork is developed in the context of the iris geometry, and an optimum form for such a meshwork is derived. A moderate improvement on the performance is obtained by allowing the iris to stretch nonlinearly. Comparison of the optimum mesh and stretch behavior with available data suggests that the iris may approximate a structure which minimizes wear and tear.