Classifying footballers with a visual impairment: The relationship between visual function and technical performance

Objectives The classification system for blind and partially sighted football is currently based on the World Health Organisation's definition of vision impairment and does not account for the impact of impairment on performance. Therefore, governing bodies require sport-specific and evidence-based classification systems. Through analysing the relationship between vision impairment and technical performance, the study aimed to produce evidence that can be used for sport-specific classification in football for athletes with vision impairment. Design Observational study. Method Forty-five footballers with a vision impairment completed a technical football-specific performance test. Visual function was measured using tests for visual acuity, contrast sensitivity, and visual field. Spearman's correlation coefficients and decision tree analyses were used to measure the relationship between visual function and performance. Results Normalised performance was significantly related to visual acuity (r = 0.635) and contrast sensitivity (r = −0.499). There was no relationship with visual field. A single split based on a visual acuity of 2.40logMAR offered the best option for classifying athletes who can and cannot compete with their remaining vision. Contrast sensitivity and visual field could not accurately classify performance in this test. Conclusions This model would lead to those with less severe impairments being able to compete in blind football whilst reducing the maximum impairment eligible for partially sighted football. A 2.40logMAR class boundary optimally classified football performance in the participants recruited.