Multistep UV process to create surface modified contact lenses

A process for modifying the surface of a silicon-containing polymer, the process comprising the steps of:

• forming a silicon-containing polymer in a first polymerization reaction mixture, the first polymerization reaction mixture comprising a photo-initiator whereby the photo-initiator initiates the polymerization and/or crosslinking of the silicon-containing polymer;
• forming a second polymerization reaction mixture comprising the silicon-containing polymer, a polymerization monomer, a free radical initiator system and a solvent system, the polymerization monomer comprising a zwitterionic monomer, wherein a residual amount of the photo-initiator that initiated the formation of the silicon-containing polymer in the first reaction mixture is present in the silicon-containing polymer when the silicon-containing polymer is combined with the solvent system of the second polymerization reaction mixture;
• and
• polymerizing the monomer in the second polymerization reaction mixture to form a surface modification polymer on the surface of the silicon-containing polymer.