THE RELIABILITY OF THE NAC-V – A PRELIMINARY TEST

Publisher Summary This chapter discusses the reliability of NAC-V. The NAC-V system uses the corneal reflection of both eyes with a left and right eye marker calibrated to indicate the point of regard within a 60° × 45° visual field. The registration part consists of a head-mounted goggle and a transportable recording system. The system also contains a data output unit for automatic data processing. A video timer activated by the subject marks the time of each fixation during the test. Precise eye-markings are obtained by restricting head and body movements, by using adults able to maintain a steady fixation and with suitable head dimensions, and by taking more time with the calibration procedure. The aim of this experiment is to obtain optimal recordings with the NAC-V, and each recording session should be preceded by a registration of the specific precision of the origin calibration, shortening, and deviation patterns.