PARADOXICAL OPTICAL POWER INCREASE OF A DEFORMABLE LENS BY EQUATORIALSTRETCHING

Yertical scanning interference microscope measurements of the mean rad ius of curvature (ROC) of bath surfaces of constant-volume deformable, water-filled lenses were obtained before and during small displacemen t stepped equatorial stretching in the plane perpendicular to the opti cal axis, Each lens demonstrated a marked decrease of the ROC at its o ptical center: However: the ROC increased in a region halfway between the center and the outer diameter of the lens, This is indicative of c entral steepening with peripheral flattening This is contrary to the a ssumption that stretching of the equator of a deformable lens will onl y reduce its optical power.