ABSTRACT
The magnetic search coil technique is one of the most precise methods for measuring eye position. By using a dual search coil it is possible to measure eye position in three-dimensions, including torsional eye movements. The calibration method introduced in the present study is based on a minimization procedure for the unknown parameters using 500–1000 eye positions obtained during spontaneous eye movements preferably from a wide oculomotor range. The procedure depends on in vivomeasurement of spontaneous eye movements and estimation of the local magnetic fields by a special calibration cube. It has the advantage of not depending on the fixation of multiple visual targets, which makes the method suitable for non-cooperating subjects or patients and untrained animals. In order to minimize the measurement inaccuracies caused by nonuniformity of the field, the calibration cube measurement must be performed as close as possible to the eye of the test subject.
