Water-soluble blocking wax formulation

The present invention relates to contact lens manufacturing, and more particularly relates to improved compositions and methods for blocking a contact lens button (also termed a contact lens blank or precursor) for machining operations which form the button into a wearable contact lens. The invention provides, in a first embodiment, a blocking wax composition. The blocking wax comprises from about 50 to about 90 weight percent of a water-soluble continuous phase and from about 10 to about 50 weight percent of a discontinuous solid phase filler that is substantially inert to the continuous phase. The invention further provides a method for mounting a contact lens blank for machining.