Other acrylate or methacrylate monomers that may be used to impart hydrophilic properties are hydroxyalkyl monoacrylates or methacrylates such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, hydroxypropyl acrylates and methacrylates, e.g. 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl acrylate, 3-