1 Molding the lens can be carried out in several different ways. The lenses first developed in Prague were spin-cast. Three different fluids were poured into open rotating molds. The outside curvature of the lens was shaped by the mold, and the inside curvature was formed according to the speed of the rotation of the mold. The centrifugal force of the spinning mold led to the polymerization of the fluids so that the molecular chains linked to form the required hydrophilic plastic. A more reliable mass-production
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