Objective To investigate the relationship between cumulative impact exposure and oculomotor functioning in professional IndyCar series drivers.

Hypothesis Greater impact exposure will be associated with less efficient oculomotor functioning over time.

Design Longitudinal retrospective cohort.

Setting A secondary care setting associated with the IndyCar professional open-wheel automobile racing series.

Participants Professional drivers involved in at least one crash per season across three years (N=13).

Interventions (or Assessment of Risk Factors) Cumulative acceleration/deceleration forces (gs) and total events (crashes) measured via ADR chassis accelerometers from 2017–2019.

Outcome Measures Post-series oculomotor performance, including predictive saccades (horizontal time and displacement), vergence smooth pursuit (eye correlation inward and outward), and optokinetic nystagmus (OKN; percentage of gain asymmetry), measured annually with a head-mounted, clinical eye tracking system (I-PAS goggle system).

Main Results Cumulative impact exposure indicated median gs = 38.15 gs (observed range = 12.01–93.05) across 81 crashes. We conducted a two-way MANOVA examining the relationship among cumulative impact exposure, season assessed, and oculomotor performance. Findings revealed no statistically significant associations among variables, F (12, 9) = 1.646, p=.541, Wilks’ λ = .440, CI=95% [30.62,65.81]).

Conclusions We did not observe statistically significant associations among cumulative impact exposure, season assessed, and oculomotor performance in professional drivers from the IndyCar series involved in multiple crashes over three years. This pilot study is the first to be conducted with IndyCar series drivers. Findings reflect the relative stability of oculomotor performance in drivers despite exposure to the highest levels of impact conferred through multiple crashes over a three-year period.