Analysis of the crimping method of producing toric surfaces in contact lens blanks using finite element and...

One of the most common methods of producing a toric surface in a contact lens blank is crimping. This method has the advantages of being simple and cheap, but the toric surface dimensions obtained, especially at higher cylinders, can be less accurate. The relationships between the crimping parameters used to produce the toric surface and the dimensions of the toric surface obtained are not well known. If these relationships are known, improved toric surface dimensions may be obtained. In this paper, finite element analysis and experimental results obtained for these relationships are presented and discussed.