Visual function of English Premier League soccer players

Advances in dynamic visual acuity test research

The dynamic visual acuity test (DVAT) is a functional evaluation tool for the impairment and compensation of the vestibular system, which could reflect the Vestibulo-ocular reflex (VOR) function. We present an overview of DVAT research, displaying recent advances in test methods, application, and influencing factors; and discussing the clinical value of DVAT to provide a reference for clinical application. There are two primary types of DVAT: dynamic-object DVAT and static-object DVAT. For the latter, in addition to the traditional bedside DVAT, there are numerous other approaches, including Computerized DVAT (cDVAT), DVAT on a treadmill, DVAT on a rotary, head thrust DVA (htDVA) and functional head impulse testing (fHIT), gaze shift dynamic visual acuity with walking (gsDVA), translational dynamic visual acuity test (tDVAT), pediatric DVAT. The results of DAVT are affected by subject [occupation, static visual acuity (SVA), age, eyeglass lenses], testing methods, caffeine, and alcohol. DVAT has numerous clinical applications, such as screening for vestibular impairment, assessing vestibular rehabilitation, predicting fall risk, and evaluating ophthalmology-related disorders, vestibular disorders, and central system disorders.

Specific relations of visual skills and executive functions in elite soccer players

Visual and cognitive skills are key to successful functioning in highly demanding settings such as elite sports. However, their mutual influence and interdependencies are not sufficiently understood yet. This cross-sectional study examined the relationship between visual skills and executive functions in elite soccer players. Fifty-nine male elite soccer players (age: 18–34 years) performed tests assessing visual clarity (left-, right-, and both eyes), contrast sensitivity, near-far quickness, and hand-eye coordination. Executive function measures included working memory capacity, cognitive flexibility, inhibition and selective attention. Overall, visual abilities were largely correlated with executive functions. Near-far quickness performance showed a large correlation with an executive function total score as well as with cognitive flexibility, working memory, and especially selective attention. Visual clarity and contrast sensitivity were moderately correlated with the cognition total score. Most consistent correlations with the visual functions were present for working memory. These findings present an overall vision-cognition relationship but also very specific linkages among subcategories of these functions, especially meaningful relations between near-far quickness, selective attention and cognitive flexibility. Further studies are needed to investigate the neuropsychological mechanisms accounting for the correlations and possible improvements of the executive functions by training specific visual skills.

Topical Review: Visual Performance Assessments for Sport

SIGNIFICANCE

Eye care professionals seek to provide effective vision care for a variety of patient needs, including performance in sports and recreational pursuits. This review provides an analysis of common visual performance assessments, including summaries of recent clinical research from a diverse array of professional literature.Vision is recognized as an important element of sports performance. Elite athletes frequently demonstrate exceptional abilities to see and respond effectively in sports competition. Which visual factors are important and how to most effectively assess visual performance are the sources of much debate. This topical review presents an evidence-based review of the common visual performance factors assessed in athletes, beginning with guidance for conducting a visual task analysis for the variety of sports that athlete patients may compete in. An information processing model is used to provide a framework for understanding the contributions of the many visual performance factors used during sports.

Cognitive training in elite soccer players: evidence of narrow, but not broad transfer to visual and executive function

Visual and executive functions have been suggested to be crucial in high-demanding team sports. Consequently, the interest in evaluating training possibilities of these functions is relatively high. However, easily applicable training tools, as well as evidence of their efficacy, especially in the present group of age (i.e. 17–21 years) and performance level, are scarce. Therefore, the present study aimed to evaluate the effectiveness and transfer of an essential cognitive training tool (i.e. NeuroTracker [NT] three dimensional [3D] multiple-object tracking [MOT]) in youth elite soccer players. Visual and executive functions were analyzed in a pre–post test design with an intervention and a control group after 10 weeks of training twice a week. Physical activity was included as a possible covariate. Results show meaningful benefits in the trained ability (i.e. MOT) besides small but negligible improvements in visual clarity and inhibition for the intervention group. Consequently, strict single-task NT 3D-MOT seems to have little transfer to other visual or executive functions. However, future studies should investigate the effects of sport-specific dual-task NT 3D-MOT to analyze possible multitasking adaptations further.

Investigation into the dynamic visual acuity of skilled cricketers using a continuous motion task

BACKGROUND

Great demands are imposed upon the perceptual-motor system when undertaking ball-throwing and -hitting tasks including cricket. That is, performers must detect and resolve object details while on the move - something referred to as dynamic visual acuity (DVA). The present study aimed to investigate DVA in skilled cricketers and non-cricketers using a more immediate or real-time assessment.

METHODS

Skilled cricketers and non-cricketers had to detect the presence of the gap within a Landolt-C ring as it moved horizontally or vertically, while progressively increasing the size until the participants registered a response. Measures were taken as the mean (dynamic) minimum angle of resolution of the object size at the moment that participants correctly responded to the gap. Objects would move at either a high, medium or low velocity.

RESULTS

There was greater dynamic visual acuity in the skilled cricketers compared to non-cricketers (P<0.05). There was a reduced negative influence of object velocity on dynamic visual acuity in the skilled cricketers compared to non-cricketers (P<0.05).

CONCLUSIONS

We suggest these findings contribute to the growing evidence surrounding DVA within ball-throwing and -hitting sports, while making some assertions as to the implications for the cricket performance setting.

The Effect of Visual Function on the Batting Performance of Professional Baseball Players

This report evaluates the role of the combined visual abilities of acuity, contrast sensitivity and presentation time on plate discipline and baseball batting performance. A visual function test (EVTS) was performed on 585 professional baseball players. The results were compared to several common plate-discipline measures. The EVTS test provides a single measure combining target size, contrast and presentation time. Correlations (statistically significant) were found between this measure and several plate discipline metrics (InzoneSwingPct, inzoneFbSwingPct, ChasePct, FbChasePct, BBperPa). Years of major league service did not appear to be related to visual ability. When comparing the best and worst 20% groups based on visual ability, statistically significant improvements ranging from 11.6% in BBperPa to 3.5% in inzoneSwingPct were noted in the better visual function group. Effect sizes ranged from 0.278 to 0.387. These results demonstrate the relationship between basic visual function and batting performance. These are the first results, on a large group at the professional level, to demonstrate this relationship statistically. These results may aid player selection, indicating that batters with better visual function are more likely to be successful when batting and more productive for their team.

Static and dynamic visual acuity and refractive errors in elite football players

BACKGROUND

The aim of this study was to investigate static and dynamic visual acuity, refractive error, and the use of visual compensation of elite football players.

METHODS

From 2015 to 2017, 147 professional players from five teams were analysed. Screening consisted of a survey about the use of visual correction, and measurement refractive error, static visual acuity and dynamic visual acuity. Refractive error was assessed using an autorefractor. Distance static visual acuity was evaluated using a Snellen chart. Dynamic visual acuity was measured at five metres using the software COI-SV. All athletes were male with a mean age of 24.6 ± 4.1 years.

RESULTS

The mean refractive error of the athletes was -0.04 ± 0.83 D, and 16.4 per cent were myopic. Statistically significant differences were found for dynamic visual acuity (p = 0.033), based on the position occupied. Goalkeepers displayed the best dynamic visual acuity and forwards had the lowest values (0.82 ± 0.14 and 0.62 ± 0.17, respectively). The forwards presented with the highest prevalence of myopia and goalkeepers the lowest, at 22.5 per cent and 12.5 per cent, respectively. All goalkeepers who needed to use a correction for play used it, whereas only 16 per cent of the forwards who needed a correction used it.

CONCLUSION

Dynamic visual acuity of forwards is lower than that of other players. Twenty-five per cent of players who need to use visual correction to practice sports actually use it.