DETERMINATION OF THE SURFACE PARAMETERS FOR ASPHERIC APHAKIC LENSES

Two methods are proposed for aspherical surface evaluation - scanning and interferometry. Each of these methods enables the determination of the radius of curvature at the lens vertex, the asphericity, astigmatism, rotation asymmetry, surface topography and the deviation of the surface from following the theoretically stated shape. While the scanning technique is low cost and simple, the interferometric technique (which needs optical arrangements) gives more information about the surface quality. These methods, combined with a computer, establish powerful instruments for controlling lens production.