Properties of siloxane-containing hydrogels were investigated with formulations of siloxane-containing monomer (TRIS) and/or poly(dimethylsiloxane) macromers with hydrophilic monomers such as 2-hydroxyethyl methacrylate (HEMA) and N,N-dimethyl acrylamide (DMA). Phase separation behavior of siloxane-containing hydrogels was found to be affected mainly by compositions of siloxane-based hydrophobic/hydrophilic monomers. (C) 2007 Elsevier B.V. All rights reserved.