Auxiliary lens holder device for use with a keratometer

Claim 1

A lens holder device for a keratometer including an eyepiece, a substantially circular front face plate having a centrally located objective lens therein, an annular lip projecting axially forwardly from the face pate, diametrically opposed pairs of mire signs on the face plate, said lens holder device comprising: a generally flat circular disc. a slot in the disc extending inwardly, in a general radial direction from the circumferential edge thereof beyond the center of the disc, said slot defining a U-shaped edge including side edge portions and an arcuate inner portion continuous with said side edge portions, said U-shaped edge having a continuous inwardly opening groove therein, said slot being of the size to accommodate an auxiliary optical trial lens therein with the edge of the trial lens positioned in the groove, said disc being of the size to permit the circumferential edge thereof to frictionally engage the inner surface of the forwardly projecting annular lip of the keratometer to mount the disc on the latter in forwardly spaced relation with respect to the objective lens of the keratometer, the slot in the disc being oriented in the vertical direction when the disc is mounted on the keratometer, with the groove in the disc being positioned forwardly of the annular lip, whereby an auxiliary trial lens seated in the arcuate edge portion of the slot will be centered with respect to the keratometer objective lens.