OcuTrace: Smartphone Oculomotor Recording for Neurology and Clinical Research

Eye movements give a direct, measurable view of brainstem, cerebellar and cortical function, yet in routine care they are judged by eye at the bedside, and objective recording is largely confined to laboratory video oculography. Clinical trials in neurodegenerative disease need oculomotor measures that are objective, repeatable and collected often, ideally at home. We propose OcuTrace, an open platform built for the smartphone that presents standardized oculomotor tasks, tracks the iris on the device, and returns quantitative measures with raw traces rather than diagnoses. The strategy puts research use first: deploy the tool as an exploratory endpoint in academic studies and sponsored trials, accumulate validation evidence, and then seek clearance as a measurement device. A browser prototype that runs the full task battery and reports each task's measures is publicly available. In synthetic recordings with known nystagmus, it recovered beat direction in every case and slow phase velocity within 0.7°/s, including a recording with simulated head movement and video compression. On synthetic eye position traces, it also recovered saccade latency within one video frame and saccade, pursuit and optokinetic gains within 1%. We describe the technical limits of consumer cameras, a five study validation program, and the regulatory, privacy and equity safeguards required before patient use.