A Method of Measuring Eye Movemnent Using a Scieral Search Coil in a Magnetic Field

With the subject exposed to an alternating magnetic field, eye position may be accurately recorded from the voltage generated in a coil of wire embedded in a scleral contact lens worn by the subject. Using two magnetic fields in quadrature phase and two coils on the lens, one may measure horizontal, vertical and torsional eye movements simultaneously. The instrument described has an accuracy and linearity of about 2 per cent of full scale, a resolution of 15 seconds of arc and a bandwidth of 1000 cyles per second.