THE MEASUREMENT AND ANALYSIS OF THE 3-DIMENSIONAL FORM OF CURVED SURFACES

In an attempt to reduce manufacturing costs, contact lenses are manufa ctured using a cast moulding technique. If quality is to be maintained , it is essential that the mould components are manufactured to very h igh standards, with particular emphasis being placed on the curvature of the optical surfaces. If these surfaces are to be accurately measur ed and described, then they must be considered in three dimensions. Se veral different measurement instruments have been considered for this purpose, and three-dimensional numerical algorithms developed for asse ssment of the data from these instruments.