Pad transfer printing method for making colored contact lenses

Abstract

The invention provides a method for producing colored contact lenses with high quality color images. The method of the invention comprises the steps of (a) providing a water based ink in at least one cliche wherein a pattern to be printed on the contact lens has been created; (b) transferring the water based ink from the cliché to at least a surface of at least a contact lens forming mold by means of at least a transfer pad; (c) at least partially curing the ink transferred on the mold to form a colored film; (d) dispensing a hydrogel lens-forming material into a lens-forming cavity of the mold; and (e) curing the lens-forming material within the lens-forming cavity to form the contact lens, whereby the colored film detaches from the molding surface and becomes integral with the body of the contact lens; characterized in that the relative air humidity in the immediate vicinities of the transfer pad/s is kept higher than 50% at standard temperature and pressure conditions during ink transfer.

Dependencies are inferred from the claim text.