Triangular Pursuit - Ocular Motor Training Standards
Triangular Pursuit is a free browser drill where a target travels around a triangle. You follow it along the straight edges and through the sharp corners, where it must change direction. Choose a speed and duration, press start, and keep tracking the target around each corner.
Tracking visual stimuli along closed geometric polygons demands continuous coordination between horizontal and vertical extraocular muscle groups. When a target moves along the straight edges of an equilateral triangle, the ocular motor system engages smooth pursuit across non-cardinal diagonal vectors, requiring the brainstem to balance horizontal pontine signals (PPRF) with vertical midbrain commands (riMLF).
The primary neurophysiological challenge occurs at the triangle's acute vertices. As the target reaches a corner and abruptly changes course, retinal slip velocity drops instantaneously while position error escalates. Seminal investigations by de Brouwer et al. (2002) and Heinen et al. (2005) demonstrated that catch-up saccades are triggered by an integrated neural calculation of both position error and instantaneous slip, initiated within frontal eye field (FEF) and supplementary eye field (SEF) decision circuits.
Without adequate ocular motor training, gaze routinely overshoots sharp vertices, resulting in multi-saccade searching corrections and disrupted visual perception. However, repetitive geometric tracking activates cerebellar forward internal models (Bennett & Barnes, 2006; Barnes, 2008), enabling the predictive deceleration of smooth pursuit as the target approaches known vertices and accelerating foveal re-acquisition onto the subsequent vector leg.
The Triangular Pursuit drill trains this geometric agility. By guiding a target continuously along a triangular trajectory, it challenges both constant-velocity diagonal tracking and acute corner re-anchoring. Advanced toggles such as 'Hide Line' remove visual path indicators to test pure sensorimotor tracking, while 'Random Speed' introduces unpredictable acceleration profiles to prevent mechanical timing habits.
Hardware latency adds display quantization (~16.7 ms at 60 Hz, ~6.9 ms at 144 Hz) and input polling intervals (~8 ms at 125 Hz vs ~1 ms at 1,000 Hz), as documented by Woods et al. (2015). All scores remain stored strictly in local browser storage.
Scope note: this is browser-based visual-motion practice. It does not record eye position, diagnose an eye or neurological condition, or replace clinician-directed vision therapy. Stop for pain, dizziness, nausea, persistent blur, double vision, headache, or unusual visual symptoms.