The present invention provides silicone hydrogel materials having relatively high oxygen permeability and a relatively low modulus. The relatively-low modulus is achieved by adding a chain transfer agent into a polymerizable fluid composition in an amount sufficient to provide to the resultant silicone hydrogel material with a reduced modulus. In addition, the invention provides silicone hydrogel contact lenses comprising a silicone hydrogel material of the invention, a method for making a silicone hydrogel material of the invention, and a method for making a silicone hydrogel contact lens of the invention.