Vertical and Horizontal Eye Movement Recording in the Unrestrained Cat

A simple electromagnetic system is described which allows simultaneous monitoring of vertical and horizontal eye movements in the unrestrained cat. A restricted magnetic field is induced through a coil fixed to the zygomatic bone, under the skin. The coil leads led subdermally to a skull implanted pedestal are connected to a 15000 Hz sine-wave generator. The induced field is detected through a small coil stitched to the side of the eyeball between the iris and medial rectus muscle attachment. The detecting coil leads are connected to the head pedestal connector, then sent to a detecting amplifier whose output is implanted perpendicular to the first provides eye movement monitoring in the other direction of space.