Hydrogel contact lenses that are derived from a polymerizable composition including at least one hydrophilic monomer and at least one phosphine-containing component are described. The hydrogel of the contact lenses can be a silicone hydrogel or a non-silicone hydrogel. Use of polymerizable compositions comprising a phosphine-containing component can be cured under both inert and air atmospheres, and can be used to form hydrogel contact lenses having improved shape retention properties, having improved resistance to discoloration. Batches of hydrogel contact lenses and methods of making hydrogel contact lenses are also described.