Prevalence of binocular vision dysfunctions in professional football players

Clinical relevance: The extent of binocular vision dysfunction in elite soccer players needs to be determined as it may impact performance.

Background: The purpose of the study was to investigate the prevalence of binocular vision dysfunctions in elite soccer players.

Methods: One hundred and seven professional soccer players were evaluated. Refractive error was measured and the following binocular vision parameters were assessed: horizontal and vertical phoria for distance and near vision, the values of break and recovery for negative and positive fusional vergences at distance and near vision, vergence facility at distance and near vision, monocular accommodative facility at near vision, and near point of convergence (break and recovery points). All the athletes were men with a mean age of 24.4 ± 4.8 years.

Results: No athlete was diagnosed with divergence excess, divergence insufficiency, or basic exophoria. About 13.0% of the athletes have binocular vision dysfunctions related to esophoria (0.9% with esophoria at near vision and 12.1% with esophoria at distance and near vision). About 10.3% have convergence insufficiency and 2.8% were diagnosed with fusional vergence dysfunction. The only accommodation-related parameter analysed was accommodative infacility, and 6.5% of the athletes had this dysfunction. Vertical phoria was present in 3.7% of the athletes. No statistically significant differences were found based on in athletes with respect to ethnicity, position occupied on the field, age, ametropia or laterality.

Conclusion: The overall prevalence of binocular vision dysfunction in elite soccer players was 36.4%. The most prevalent dysfunctions are related to the presence of esophoria (13.0%). The values found point out the need to include binocular vision assessment protocols in the visual assessment routine for athletes.