Normative visual performance standards in male professional football players: a comprehensive assessment of visual acuity, binocular function, and visuo-cognitive abilities

CLINICAL RELEVANCE: Visual performance plays a fundamental role in sports, contributing to decision-making, spatial awareness, and object tracking. Establishing normative values for key visual functions supports performance assessment and training optimisation in athletes. BACKGROUND: This study aimed to evaluate visual acuity, refractive error, binocular function, and Visuo-cognitive abilities in professional football players to establish normative visual performance standards across different levels of athletic ability. METHODS: Visual assessments included static and dynamic visual acuity, refractive error, binocular vision (phoria, fusional vergence, vergence facility, and accommodative facility), and stereopsis. Visuo-cognitive abilities, such as multiple object tracking, reaction time, and peripheral perception, were also evaluated. The results were classified into five performance levels: Elite (10th percentile), Proficient (25th percentile), Average (50th percentile), Insufficient (75th percentile), and Dysfunctional (90th percentile). Statistical analyses were performed to determine normative thresholds and identify significant differences across these performance levels. RESULTS: A total of 262 male professional football players (mean age 24.6 ± 4.8 years) were assessed. Visual acuity averaged 1.09 ± 0.20, with Elite-level performance at 1.26 (6/4.8) and Dysfunctional-level at 0.90 (6/6.7). Dynamic visual acuity was 0.72 ± 0.17, with thresholds at 0.62 (6/9.5) (insufficient) and 0.52 (6/11.5) (Dysfunctional). Refractive error showed minimal anisometropia (0.20 ± 0.41D). Phoria status was orthophoric at distance (0.0 ± 2.1Δ) and exophoric at near (2.2 ± 4.7Δ). Accommodative facility averaged 11.7 ± 4.6 cpm. Stereopsis at distance averaged 1.85 ± 0.16 log arcsec, with Elite performance at 1.78 log arcsec and Dysfunctional at 2.00 log arcsec. Peripheral span averaged 40.7 ± 11.9, while multiple objects tracking and visual reaction time averaged 1623.3 ± 430.5 ms and 327.4 ± 37.8 ms, respectively. CONCLUSION: Normative visual data is provided for male professional football players, including visual acuity, binocular vision parameters, and visuo-cognitive skills, offering a reference for assessing and optimising performance in football.