Crosslink agents used to copolymerize at least one hydrophilic monomer with at least one lens monomer typically used to prepare polymeric materials for ophthalmic lenses. The crosslink agents have a relatively high selectivity for the hydrophilic monomer and limited reactivity with the crosslink agent used to polymerize the lens monomer. Accordingly, the invention is also directed to a hydrophilic crosslinked polymer that comprises at least two monomeric units and at least two different crosslink units. The use of the dual crosslink system provides an improved means to control the final chemical, physical and structural characteristics of the resulting polymer.