Patent ID: 7688431

Claim:
An apparatus for comparatively demonstrating optical properties of eyewear lenses comprising: an illumination source that comprises at least some emission in a first wavelength range of 380-500 nm and at least some emission in a second wavelength range at measurably longer visible wavelengths; a target that creates an image on a light path when illuminated by the illumination source; a first test lens comprising an eyewear lens material, wherein the first test lens is illuminated by the light path from the target and transmits at least some of the light path, and wherein the first test lens can be interchangeably replaced in the light path by a second test lens; and a detector of the light path that displays the target image transmitted through the first or second test lens to allow sequential comparison of the first test lens' effect on the target image and the second test lens' effect on the target image.