Visual Performance and Sports: A Scoping Review.

Vision is central to success in nearly all sports, and there is an emerging body of research investigating the links between visual abilities and athletic performance. This preregistered scoping review seeks to clarify the topics of study, methodologies used, populations under investigation, researchers, and disciplines driving this field. Systematic searches of English-language articles were conducted in PubMed and Web of Science, with additional literature identified through bibliographic searches. Six hundred sixty-seven articles published between 1976 and 2023 were identified with 547 empirical studies, 58 review articles, 20 commentaries, and 4 meta-analyses, among others. Among the empirical papers, 411 reported on visual assessments and 98 on vision training interventions. The most represented sports included baseball, soccer, basketball, and cricket, with over 150 articles reporting on professional, elite, or Olympic athletes. This scoping review describes the breadth of this emerging field, identifies its strengths and weaknesses, and provides recommendations for future improvement.

The Uses of Vision Data in Selecting Players for the Major League Baseball Draft.

SIGNIFICANCE: This report illustrates the potential uses of vision data in helping teams select players during the draft. PURPOSE: Visual performance has gradually gained recognition in baseball as a tool that can optimize on-field performance. It also may be useful in player development programs that gradually move players toward the major league. METHODS: Recently, over the past 5 years, vision data from six different major league teams were used by the authors to assess prospective players before the annual Major League Baseball (MLB) draft. One thousand three hundred forty-three vision forms were evaluated representing 759 different players. Their vision data were retrospectively analyzed using a novel grading method to advise teams on the visual readiness of prospects for success in MLB. RESULTS: On a one (best)-to-six (worst) vision scale, the average vision score was 2.080 ± 1.171. Sixty-eight percent (320/473) of the players with good vision scores were drafted, 66% (185/281) of the players with moderate vision scores were drafted, and only 1 player with a poor vision score was drafted. There was a statistically significant difference in the amount of signing bonus received by draftees with better vision scores compared with those with lower vision scores (P < .003 to P < .001). Draftees with the highest vision scores also received the highest signing bonuses as they entered MLB. CONCLUSIONS: For both potential draftees and teams, the vision score seems to be a valuable tool in selecting players for the MLB draft. Adding the pre-draft visual assessment score to a team's projection model could help reduce the uncertainty surrounding the player draft and future service to the team.

Comment on Nascimento et al. Citations Network Analysis of Vision and Sport. Int. J. Environ. Res. Public Health 2020, 17, 7574.

In October 2020, the paper [...].

Review: Vision and On-field Performance: A Critical Review of Visual Assessment and Training Studies with Athletes.

SIGNIFICANCE: Sports vision is an emerging field that seeks to establish the relationships between visual function and sports performance. Here we provide the first critical review of empirical studies that attempt to link visual assessments and vision training to competitive game performance.Vision is essential to producing controlled movement, and therefore, it is intuitive that better visual abilities should relate to better sporting performance. This notion has been central to the field of sports vision, an area of study that seeks to determine the visual skills that underlie optimal sports performance and investigate approaches to train these abilities to improve sports performance. Although this field now contains hundreds of published articles addressing visual assessment and training in athletes, relatively few have attempted to directly link these capabilities to on-field production statistics from competitive matches. The objectives of this article are both to describe the theoretical and experimental framework necessary for such research and to critically review the empirical literature that has attempted to directly link visual assessments and/or training to athletic performance. We begin by describing why such associations are important and then provide an evidence-based framework for evaluating the quality of research in this domain. This is followed by a summary and review of the qualified literature that has addressed either relationships between baseline assessments and game performance or the effects of visual training interventions on game performance. Based on this review, it is concluded that, despite promising evidence supporting the role of vision in sports performance and improvements due to training, the specialty is still in need of methodological improvements. It is recommended that studies aim for larger better-powered studies, consistent and precise outcome measures, and greater scientific rigor such as obtained through randomized placebo-controlled designs with pre-registration of hypotheses.

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.

The Hand-eye Coordination of Professional Baseball Players: The Relationship to Batting.

SIGNIFICANCE: A visuomotor skill (eye-hand visual-motor reaction time [EH-VMRT]) important for baseball performance is described. Eye-hand visual-motor reaction time represents the integration of visual information, perceptually based decisions, and motor movements to accomplish a specific task. The speed at which this occurs depends on many factors, some visual, some perceptual, and some motor related. PURPOSE: The purpose of this study was to describe the EH-VMRT ability and evaluate its relationship to the baseball batting performance of professional baseball players. METHODS: A commercially available EH-VMRT system was used on 450 professional baseball players. Results were retrospectively compared with standard, career, plate discipline metrics. RESULTS: Statistically significant correlations were found between the EH-VMRT metrics and plate discipline batting metrics. Better EH-VMRT ability also correlated with longer service in, and likelihood to achieve, the major-league level. The better (top 20%) EH-VMRT group had three fewer at bats before gaining a walk (22% decrease), as well as swinging 10 to 12% less often at pitches outside the strike zone and 6 to 7% less often at pitches in the strike zone as compared with the bottom 20% group. In addition, EH-VMRT displays a threshold-like relationship with the ability to gain a walk. CONCLUSIONS: These results describe the EH-VMRT ability of professional baseball players and show a significant relationship between the EH-VMRT ability and batting performance. These results may suggest a possible role in player selection, indicating that batters with better EH-VMRT may be more likely to reach the major-league level and be more productive for their team. Further studies will be needed to demonstrate whether training better EH-VMRT results in improved batting performance.

Case Report: Use of Sports and Performance Vision Training to Benefit a Low Vision Patient's Function.

SIGNIFICANCE: Despite our inability to attenuate the course of many ocular diseases that can ultimately lead to loss or significantly decreased visual function, this report describes a potential technique to aid such patients in maximizing the use of the vision that remains. PURPOSE: The aim of this study was to demonstrate the applicability of utilizing sports vision training to improve objective and subjective visuomotor function in a low vision patient. CASE REPORT: A 37-year-old woman with Usher syndrome presented with reduced central visual acuity and visual field. Although we were unable to reverse the damage resulting from her diagnosis, we were able to improve the use of the remaining vision. A 27 to 31% improvement in hand-eye coordination was achieved along with a 41% improvement in object tracking and visual concentration. Most importantly, following the 14-week training period, there was also a subjective improvement in the patient's appreciation of her visual ability. CONCLUSIONS: The sports vision literature cites many examples in which sports vision training is useful in improving visuomotor and on-field performance. We hypothesized that these techniques may be used to aid not only athletes but also patients with low vision. Despite suffering from reduced acuity and a limited visual field, these patients often still have a significant amount of vision ability that can be used to guide motor actions. Using techniques to increase the efficient use of this remaining vision may reduce the impact of the reduced visual function and aid in activities of daily living.

The Refractive Error of Professional Baseball Players.

PURPOSE: High levels of visual acuity are required to hit a baseball effectively. Research has shown that any decrease in vision is likely caused by low-order optical aberrations. This study is designed to validate the SVOne autorefractor, and describe the amount and type, of low-order optical aberrations present in a large cohort of professional baseball players. METHODS: A retrospective chart review on the 608 Major League Baseball players evaluated during the 2016 Spring Training Season was performed. Results for a subset of players who had both manifest refraction as well as autorefraction were calculated. Subsequently, after determining the accuracy of the autorefraction system in this population, refractive results for the entire population were determined. RESULTS: There was a borderline statistically significant difference in mean spherical refractive error (M) between the manifest refraction and the SVOne auto refraction (-0.273D in the manifest refraction method vs. -0.503D in the SVOne method, P = .06) in the subset of athletes who underwent both tests. Additionally, there was no difference in the J0 or J45 cylindrical component vectors for each method. For the entire eligible population, the SVOne autorefraction system found a mean spherical refractive error (M) of -0.228D, a J0 value of -0.013D, and a J45 value of -0.040D. CONCLUSIONS: These data suggest that the SVOne autorefraction system is generally able to measure the refractive error in the baseball population. The system was slightly biased, often reporting more myopia in myopic subjects. Thus, careful evaluation of the refractive status of these athletes coupled with careful subjective refractive correction for those with less than average vision for baseball is strongly suggested.

Thoughts on ocular dominance-is it actually a preference?

BACKGROUND: Ocular dominance has been studied for many years, and there have been many attempts to correlate eye dominance with athletic performance. Although many reports have failed to show a correlation, some reports have shown a relationship between sports performance and eye dominance. METHODS: This report reviews some of those studies and the tests of eye dominance used in the reports. Additionally, we review the physical basis of eye dominance and the role of the binocular visual system in its determination. Lastly, a review of common facts and fallacies relating to ocular dominance is provided. RESULTS/CONCLUSION: It is suggested that the visual system is designed as a binocular system, and only tests that allow for maintenance of binocular vision during the determination of ocular preference should be used if an accurate evaluation is to be made.

The visual function of olympic-level athletes-an initial report.

OBJECTIVE: To describe the visual functions of Olympic-level athletes and begin to describe any differences between sports. METHODS: A commercially available testing system was used to evaluate 157 Olympic-level athletes. These sports vision evaluations were therefore performed under standardized conditions. Visual functions, tested at a distance, consisted of monocular visual acuity, contour and random dot stereoacuity, and contrast sensitivity. RESULTS: Boxers and track-and-field athletes demonstrated mean logMAR visual acuities between -0.078 and -0.060. All others demonstrated results better than -0.121. There were statistically significant differences and suggestive trends in the visual acuity in the right and left eyes between the track-and-field and archery and track-and-field and softball, and between softball and boxing (range P=0.0005-0.0243). Mean distance contour stereoacuity of the archers was 62 arcsec, worse than the soccer, softball, and speed skaters. All athletes demonstrated similar contrast sensitivity results at low spatial frequencies, whereas at higher spatial frequencies, softball players performed better than did the speed skaters, track-and-field, and volleyball athletes. CONCLUSIONS AND APPLICATION TO CLINICAL PRACTICE: There seems to be a unique set of visual skills that are common to athletes in certain sports. In addition, visual performance measures vary between sports at the Olympic level. The ability to identify the visual needs for an athlete who wishes to participate in a given sport, and to correct any deficits an athlete may have, could lead to more success, at the elite and amateur levels.

Optic neuropathy in a child with alopecia.

A 4-year-old boy develops an insidious optic neuropathy, of unknown etiology, followed shortly thereafter by a focal patch of hair loss (biopsy proven-alopecia areata) on the back of his head. The temporal aspects of these findings suggest a common, likely inflammatory, etiology.

Optical aberrations in professional baseball players.

PURPOSE: To determine the presence, type, and size of optical higher-order aberrations (HOAs) in professional athletes with superior visual acuity and to compare them with those in an age-matched population of nonathletes. SETTING: Vero Beach and Fort Myers, Florida, USA. METHODS: Players from 2 professional baseball teams were studied. Each player's optical aberrations were measured with a naturally dilated 4.0 mm pupil using a Z-Wave aberrometer and a LADARWave aberrometer. RESULTS: One hundred sixty-two players (316 eyes) were evaluated. The HOAs were less than 0.026 mum in all cases. Spherical aberration C(4,0) was the largest aberration with both aberrometers. There were small but statistically significant differences between the aberrometers in mean values for trefoil C(3,3) and C(3,-3) and secondary astigmatism C(4,2). Although statistically significant, the differences were clinically insignificant, being similar at approximately 0.031 diopter (D) of spherical power. A statistically significant difference was found between the professional baseball players and the control population in trefoil C(3,-3). These differences were clinically insignificant, similar to 0.071 D of spherical power. CONCLUSIONS: Professional baseball players have small higher-order optical aberrations when tested with naturally dilated pupils. No clinically significant differences were found between the 2 aberrometers. Statistically significant differences in trefoil were found between the players and the control population; however, the difference was clinically insignificant. It seems as though the visual system of professional baseball players is limited by lower-order aberrations and that the smaller HOAs do not enhance visual function over that in a control population.

Effects of head tilt on stereopsis.

PURPOSE: Depth perception is an important part of many everyday tasks such as driving, catching a ball, and threading a needle. Binocular cues such as horizontal retinal image disparity (HRID) are significant cues to depth and play an important role in overall depth perception. Stereoscopic threshold (stereoacuity) is directly proportional to the interpupillary distance (IPD). Therefore, decreasing the IPD would predictably decrease streoacuity. Tilting the head toward one shoulder or the other will decrease the horizontal separation between the eyes thereby decreasing the IPD. This results in a decrease in stereoacuity. Although this has been demonstrated mathematically it has yet to be shown to have clinical significance. METHODS: All subjects had normal vision, eye alignment, and ocular health. Stereoacuity was evaluated using the BVAT distance stereoacuity test with the subject's head upright as well as when tilted to the right and left at 10, 20 and 30 degrees. A digital potograph verified the head tilt and IPD. The median stereoacuity for each head position was analyzed using the Friedman Test and pair-wise comparisons were made between different head positions using the Paired T-Test. RESULTS: 77.2% (44/57) of subjects exhibited a decrese in stereoacuity of at least 15 arc-sec with head tilt. The median change in stereoacuity from the upright was 22.5 to 45 arc-sec for the 6 head tilt positions (P 0.001). Although statistically the decrease in stereoacuity was not linear with regard to head tilt, there was an almost linear correlation between increasing head tilt and decreasing stereoacuity. CONCLUSIONS: Head tilt to either the left or right creates a relative decrease in interpupillary distance with regards to the horizontal plane. This effective decrease in IPD results in a decrease in a subject's stereoacuity. Additionally, the greater the head tilt, the greater the loss of stereoacuity. This information is useful in counseling individuals, especially those engaged in activities where stereoacuity is critical to performance, to make a special effort to maintain a straight head position.

A symptom survey and quality of life questionnaire for nasolacrimal duct obstruction in children.

PURPOSE: To develop and validate a new parental questionnaire addressing symptoms and health-related quality of life (HRQL) in childhood nasolacrimal duct obstruction (NLDO). DESIGN: Cross-sectional study. PARTICIPANTS: Children ages 6 to younger than 48 months with and without clinical signs of NLDO. METHODS: A new questionnaire was developed using semistructured interviews with parents of children with NLDO and through discussions with expert clinicians. Questionnaires were completed by parents of children with and without NLDO. Cronbach's alpha was calculated as a measure of internal-consistency reliability. Factor analysis was used to evaluate a priori subscales: symptoms and HRQL. Discriminant construct validity was assessed by comparing questionnaire scores between children with and without NLDO and between affected and unaffected eyes of children with unilateral NLDO. Instrument responsiveness was determined by comparing presurgical and postsurgical intervention scores in a subset of NLDO patients who underwent surgical treatment. MAIN OUTCOME MEASURE: The NLDO questionnaire score. RESULTS: Eighty-seven children were enrolled, 56 with and 31 without NLDO. All but 2 questions on the questionnaire showed a good distribution of responses, a high correlation with the rest of the questionnaire, and excellent discrimination between patients with and without NLDO. Cronbach's alpha values were good for the overall questionnaire (0.95), and for 2 predetermined subscales: symptoms (0.95) and HRQL (0.85). On a 0 to 4 scale, NLDO patients had worse scores compared with non-NLDO patients for both symptoms (mean difference, 2.1; 95% confidence interval [CI], 1.9-2.3) and HRQL (mean difference, 1.2; 95% CI, 0.9-1.5) subscales. The NLDO patients had worse scores before intervention compared with after intervention for both the symptoms (mean difference, 2.2; 95% CI, 1.6-2.9) and HRQL (mean difference, 1.4; 95% CI, 0.8-2.1) subscales. Finally, NLDO patients had worse symptom scores for affected eyes compared with unaffected eyes (mean difference, 2.3; 95% CI, 1.9-2.6). CONCLUSIONS: This novel NLDO questionnaire is useful in quantifying parental perception of symptoms and HRQL in childhood NLDO. The questionnaire may have a role in future clinical studies of NLDO.

The effect of laser refractive surgery on the on-field performance of professional baseball players.

BACKGROUND: The aim of this study was to determine the effect of laser refractive surgery on the offensive performance of professional baseball players. METHODS: Extensive search of the public media was conducted to determine which major league baseball players had undergone laser refractive surgery and when the procedure was performed. Baseball performance data were then used to determine presurgery and postsurgery baseball performance averages. A total of 17 position players were identified; however, 5 of these players were not considered in the analysis owing to insufficient playing experience either before or after the laser procedure. RESULTS: No statistically significant or practically significant difference was found between the presurgery and postsurgery means on either on-base percentage (P = 0.31), batting average (P = 0.39), slugging percentage (P = 0.66) or on-base plus slugging (OPS; P = 0.997) of major league baseball players. CONCLUSIONS: These preliminary findings suggest that professional baseball players should not expect a laser refractive surgical procedure to significantly improve their offensive baseball performance, despite the elimination of glasses or contact lens wear.