A method for measuring horizontal and vertical eye movement chronically in the monkey.

Abstract
Eye movements are measured chronically in the monkey by surgically implanting a coil of fine wire upon the eyeball beneath the bulbar conjunctiva and recti insertions. The ends of the coil are led to a connector mounted on the monkey''s head. When the animal is exposed to 2 alternating magnetic fields in spatial and phase quadrature, signals generated in the coil on the eye may be phase detected to produce 2 voltages proportional to horizontal and vertical eye position with an accuracy of 15 min. of arc. This technique makes it possible to record eye movements conveniently and accurately in the experimental animal in long- or short-term experiments on oculomotor function as well as enabling the experimenter to control eye movements by training the animal in visual tracking tasks.