Oculomotor testing is used worldwide for diagnostic screening of balance and other neurological disorders. Test parameters were not standardized until recently when a new US standard was implemented. ANSI standard S3.45-1999 defines procedures for performing and reporting a battery of tests for the evaluation of human oculomotor function. We propose to develop a portable, calibrated, low-cost device as a stimulus and recording system for oculomotor testing that meets the new standard. The target stimulus will be a laser diode spot whose projected position is commanded by a microcontroller. Beam scanning and positioning capabilities will provide stimuli for horizontal and vertical saccadic, pursuit and gaze oculomotor tests. Eye movement DC electro-oculographic recording will be provided by a high quality, mixed analog-digital circuit. The system will be interfaced with a notebook PC computer for portability. A graphical user interface on the PC will be provided for testing, analysis and data storage. Ten normal subjects will be tested with the device while performing oculomotor tests for saccadic, gaze holding and sinusoidal tracking with parameters required by the new standard. Each subject will be tested on the same day with both the proposed system and an industry-standard light bar system for data comparison. There is a need for a low cost, accurate, automatically calibrated stimulation and recording system that satisfies the new ANSI standard. This device should be transportable for use in bedside testing. This product will provide accurate information for clinicians in all areas interested in identifying patients with sensory and brain disorders.