ABSTRACT
The coil signals were processed by dual-phase detectors and three-dimensional eye position components were calculated using a custom algorithm. A related artifact was observed when the wire from the coil is close to either of the eye lids. Contact with the eyelid will limit mechanically the range of accurate measurement, causing saturation and distortion effects in the torsional component. Correct positioning of the coil is therefore of great importance, especially in subjects with droopy eye lids. The scleral search coil induction coils were fixed to the sled chassis, so that eye movements were measured relative to the sled. For this reason the Video-oculography camera was also fixed to the subject helmet, which in turn was fixed to the sled. This effectively minimises any discrepancy between the several systems due to head rotation.
