A method and apparatus for performing NMR measurements suppressing contribution to NMR signals from within the borehole. The hydrolyzable polymer can be converted by hydrolysis into a hydrophilic polymer which is capable of imparting the silicone hydrogel contact lens a hydrophilic surface without post-curing surface treatment. A torque transmitter detects and transmits to the control members a signal representing the current output torque. Example compressive stress inducing layers include SiO2 and Si3N4, while example stress inducing materials include Ge, W and Co.