Have you ever wished you could improve your batting average, lower your golf score, or just play your favorite sport better? Most people who participate in sporting activities love to win or at least improve their performance. Athletes at all levels of competition spend a substantial amount of money on sports, including equipment and clothing. Yet many performances that fail are not caused by poor equipment or clothing, or even by the wrong physical movement, but by the movement being performed at the incorrect time or in the incorrect place.
A significant percentage of the general population in developed nations participate at some level in sporting activities. The National Sporting Goods Association produces yearly estimates of participation by sport and gender for the United States (available at www.nsga.org ). The eye care practitioner must recognize that sports participation crosses all lines of age, gender, race, and socioeconomic status; every patient is potentially a sports vision patient. In addition, a significant percentage of the population may not actively participate in sports but are avid spectators.
Considerable debate has taken place concerning the role of vision in sports. Vision is the signal that directs the muscles of the body to respond. The legendary football coach Blanton Collier is credited for developing the concept that “the eyes lead the body.” Vision provides the athlete with information regarding where and when to perform. Superior size, strength, speed, and agility cannot completely make up for inefficient processing of visual information. For example, if the eyes do not tell a batter where the ball is heading and when it will arrive, he or she is not going to hit it no matter how perfect the swing is. Even for the discriminating spectator, excellent visual function allows improved opportunity to enjoy watching sports. Little debate exists that vision is a critical factor in sports performance; however, even when conflicting evidence is taken into consideration, research clearly shows that successful athletes typically possess superior visual function that allows them to see and perform better than novices in sports.
The athletic community should be educated about the aspects of vision that potentially affect sports performance. To clearly communicate these aspects, the following visual elements should be discussed:
Sight: The clarity of the image on the retina and ocular health.
Motor/sensory: Fixation stability and eye movements, accommodation, vergence, and fusion; visually guided motor performance.
Information processing: Quick and accurate visual processing, interpretation, and decision-making.
Understanding the relevance of these aspects to performance provides an avenue for effective communication of specific vision care recommendations. A better-informed sports community benefits by improved access to services that potentially make sports and athletic competition safe, enjoyable, and more successful.
Overview of Terminology
The term sports vision has been used to describe many vision care services provided to athletes. Practitioners working in this area are usually involved with one or more of the following professional activities :
prevention and management of sports eye injuries;
assessment and remediation of functional vision inefficiencies that may negatively impact competitive consistency;
specialized contact lens services with emphasis on environmental factors in sports, position of gaze factors, emergency care, and attainment of optimal visual acuity;
performance-based ophthalmic eyewear services that address visual and environmental demands;
assessment of specific sports-related visual abilities;
enhancement training of specific visual abilities considered to be essential for competitive consistency for a specific sport activity;
consultation with athletes, coaches, trainers, and teams regarding visual factors and strategies related to consistent peak athletic performance.
Many in the global community are dedicated to the pursuit of athletic excellence. A critical but often neglected aspect of peak human performance is vision. The information presented in this book should help stimulate the inclusion of these specialized services in the care of athletes, no matter the level of sports participation.
In North America, the term sports vision has been associated with vision therapy designed for the enhancement of sports performance. The areas of sports vision defined earlier clearly demonstrate that many of these services are basic primary vision care services that are modified to address specific task demands. All eye care practitioners should consider visual performance factors when providing vision care services to athletic patients.
The use of special eyewear for sports is perhaps the oldest application of vision factors to performance. Daland described the early use of stenopeic slit masks by Eskimos for hunting, and many other special-purpose optical appliances have been described in the literature. Optical protection from solar radiation and glare has been used to some degree for centuries. The use of optical refractive compensation for sports has not been as frequently used, most likely for a combination of practical and aesthetic reasons. The available eyewear was not typically appropriate for use in sports. Contact lens technology did not emerge as a reasonable option for most athletes until the latter half of the 20th century, and refractive surgery options did not become advantageous until the late 1990s. Today, the benefits of significant advances in technology and designs for the correction and protection of vision are enjoyed by athletes (see Chapter 6 ).
The evaluation of vision skills in athletes has also been an area of intense interest. The earliest literature citation found is an account of the sensory and motor abilities of the legendary baseball player Babe Ruth in 1921. This report was followed later by an article discussing the role of vision in baseball. These early articles produced suggestions for procedures to assess performance potential in baseball on the basis of vision skill analysis. Interestingly, debate in the literature exists concerning the actual vision profile of the great Babe Ruth. Despite the early report that Ruth had eyesight that was 12% faster than the average person, a 1991 article reported that an ophthalmologic examination revealed amblyopia ex anopsia in his left eye. The potential role of depth perception in batting is challenged by these discrepancies in Ruth’s visual status; either he performed so well because he had superior vision skills or he was successful despite having degraded stereopsis as a result of amblyopia. Although no definitive resolution can be made from these contradictory reports, some have speculated that the unilateral vision loss was likely the result of a complication of his nasopharyngeal carcinoma rather than an undetected congenital condition. The exact role of vision in sports performance is still hotly debated, and many vision evaluation procedures have been suggested over the years in an attempt to discover the nature of this aspect of sports performance.
Because vision skills are generally recognized as a critical element to most sport performances, significant interest has been expressed in improving sports performance by using training procedures to enhance vision. Many of the visual attributes that have been identified as important in sport are amenable to training. The relevant questions are whether sport-specific visual abilities can indeed be trained and whether any improvements in visual skills transfer to improved sports performance by the athlete. Although the literature has few reports supporting sports vision training, and these reports often have significant flaws, enhancement of visual skill performance can be logically predicted to provide the athlete with a potential advantage when preparing for a competition.
The increasing interest in sports and the role of vision in sports has produced the impetus for the formation of organizations to facilitate professional communications. The United States was the first to form an entity through the establishment of the Sports Vision Section of the American Optometric Association (AOA) in 1978. Like many similar organizations, the AOA Sports Vision Section afforded practitioners a venue for continuing education, for obtaining updates through an e-newsletter, for a referral network through a member directory, and for gaining access to professional materials such as the Sports Vision Guidebooks and the Sports Vision Bibliography . The Section was also active in interprofessional relations with other organizations, such as the U.S. Olympic Committee, Special Olympics, Amateur Athletic Union (AAU) Junior Olympics, American College of Sports Medicine, National Athletic Trainers’ Association, and National Collegiate Athletic Association. The Section provided practitioners and students opportunities to participate in sports vision activities, such as the sports vision screening program at the annual AAU Junior Olympic Games. In 2016, the Sports Vision Section was converted to the Sports and Performance Vision committee ( www.aoa.org/optometrists/tools-and-resources/sports-and-performance-vision ) and continues with many of the same goals and initiatives. There have been other similarly focused groups formed recently, such as Sports Vision Pros ( www.sportsvisionpros.com ) and the International Sports Vision Association ( www.sportsvision.pro ). Ultimately, groups such as the AOA Sports and Performance Vision committee offer practitioners an opportunity to collaborate and advance the profession.
Organizations dedicated to sports vision have also been created outside the United States. The Canadian Association of Optometrists formed a Sports Vision Section in 1987, the European Academy of Sports Vision was formed in Italy in 1989, the Optometrists Association Australia established its Sports Vision Section in 1992, and the Sports Vision Association was formed in the United Kingdom in 1993. These organizations perform similar functions to the AOA Sports Vision Section in their respective regions and have helped facilitate the growth of sports vision globally.
In 1979, Pacific University College of Optometry began providing an elective course on sports and recreational vision in the optometry curriculum. All schools and colleges of optometry in North America now offer some degree of education in sports vision as part of the curriculum.
Overview of a Clinical Model of Sports Vision
Vision care for athletes should begin with the identification of visual factors that potentially contribute to peak human performance so that these specific functions can be isolated and measured, if possible. The visual demands critical to success in sports can vary tremendously. Chapter 2 details an approach to the task analysis process, a process essential to provide appropriate vision care for athletes in any sport or position. Because sports performance generally requires the athlete to process visual information and execute an appropriate motor response, the practitioner should also understand how visual information is processed to understand the exact nature of the processes occurring in skilled motor performance. A model of information processing in skilled motor performance is presented in Chapter 3 to provide a useful approach for understanding the relevant aspects of sports performance.
Once the practitioner has identified the vision factors essential to the performance of the visual tasks critical for success in a sport, an evaluation should be made to measure the quality of those skills in the most appropriate, accurate, and repeatable manner. The visual skills that correlate with successful sports performance have not been definitively identified yet, so the practitioner must rely on the available literature and professional judgment to determine the most appropriate evaluation for each athlete. Chapter 4 provides an evidence-based description of each potential vision assessment area and the relative value of each assessment area in an evaluation. Chapter 5 presents recommendations for performing team vision screenings and the unique challenges associated with providing vision care to a team. The results of a screening or evaluation should be summarized for the patient, and a performance profile is recommended in Chapter 5 to highlight areas of strength or limitation and communicate vision recommendations.
A fundamental role of the vision care practitioner is to provide expert consultation services to athletes regarding vision correction and the potential uses and benefits of ophthalmic products. Each athlete has specific variables that will affect ophthalmic recommendations. The gender, age, level of participation, combination of sports activities, and history of product use influence the choice of available options. Some athletes seek a single product to meet all visual performance needs, whereas others seek optimal products for a variety of highly specific uses. The eye care practitioner should advise athletic patients about the advantages and disadvantages of spectacles, protective eyewear, sun eyewear, contact lenses, and refractive surgery. Chapter 6 discusses the issues involved in the available modalities for vision correction, eye protection, and vision enhancement. The practitioner should help the athlete make informed decisions about the best options for his or her individual needs.
Participation in sports carries a risk of sustaining an eye injury. The vision care practitioner can perform a crucial role in the prevention of sports-related eye injuries, immediate first aid management if an eye injury occurs, referral of the athlete to an appropriate specialist if necessary, and follow-up care for the athlete who has sustained an eye injury. Chapter 7 provides an overview of assessment and management of sports-related ocular trauma from the perspective of both the athletic trainer and the eye care professional. The chapter provides recommendations for effective co-management of ocular injuries in athletes.
Sports also carry a risk for sustaining a traumatic brain injury or concussion. There is ample evidence that in addition to reduced visual processing speeds, concussions lead to binocular vision deficits, oculomotor dysfunctions and visual field deficits. Chapter 8 addresses sports vision procedures used to evaluate and rehabilitate sports-related concussions as part of a comprehensive multidisciplinary approach.
As previously mentioned, significant interest exists in determining whether sports performance can be improved by using training procedures to enhance vision. The athlete with identified visual deficiencies is logically expected to achieve improvement in affected aspects of sports performance if those deficient skills are improved to average performance levels. The athlete who possesses average, or even above-average, vision skills presents a more compelling and controversial challenge. Can the vision skills of this athlete be enhanced above the current level, and would this skill enhancement result in demonstrable improvements in sports task performance? A review of the literature concluded that most normal visual functions can be improved by specific training paradigms, although thousands of trials may be required to demonstrate enhancement. There is limited and mixed support demonstrating that traditional sports vision training can improve sports-relevant vision or manifests into better on-field performance. However, isolating one area of intervention as solely responsible for any changes in performance is quite difficult. Each sports vision practitioner develops an approach to visual performance enhancement that best suits his or her mode of practice; however, useful guidelines should be observed. Chapter 8 provides a sample of visual performance training procedures that have been used by sports vision practitioners, with a rationale and framework for developing effective training programs. Recent digital sports vision training instruments that have shown promising evidence for improving vision and sporting performance are included.
Athletes explore many options to improve performance; however, dietary intake modifications have seen recommendations vary widely over the years. Most of the focus has been on diets designed to enhance muscle performance, particularly strength, endurance, replacement and recovery. Recent research has demonstrated that certain nutrients, specifically lutein (L) and zeaxanthin (Z), can improve visual performance factors. Chapter 8 also includes an overview of modifications to diet to increase intake of carotenoids or to supplement with purified forms of L and Z. Placebo-controlled studies have found that for those athletes who experience difficulties with glare, photostress, and contrast judgment, increasing macular pigment density offers a potential method to improve these functions by enriching the natural physiology. Macular pigment density is also linked to L and Z levels in the brain, and the level present is related to functions such as cognition, reaction time, and temporal visual processing.
The final chapter deals with the unique issues pertaining to the development of sports vision services in professional practice. Challenges of internal and external marketing are discussed, and specific methods for growing this area of practice are highlighted. Chapter 9 also provides many important suggestions for establishing consistent messaging throughout the delivery of sports vision services.
The Future of Sports Vision
During the past 40 years a general increase in the use and provision of sports vision services by optometrists has been observed. Eye care practitioners are a common component in the health care service team in professional sports and many collegiate athletic departments in North America. The range of vision care services includes vision screening programs, vision correction with contact lenses, eye protection consultation, eye injury management, and visual performance enhancement training programs. These services are provided either on-site at the athletic facility or in the practitioner’s practice. Great interest in sports vision services exists within the sporting community, and the consensus is that this need is not being adequately met by eye care practitioners.
The eye care professions have considerable room for growth in the delivery of sports vision services. Many high-level athletes have never received a comprehensive vision examination and are largely unaware of the potential impact of sports vision services on athletic performance. A review of screening data collected over 10 years from Amateur Athletic Union Junior Olympic Games in the United States found that more than 29% of participants had not received eye care for more than 3 years, with more than 20% never having an examination by an eye care professional. Indeed, the rate of use of protective eyewear in sports demonstrates the limited impact that public education programs have had in the sports community. Significant growth potential clearly exists in all the areas of sports vision care listed at the beginning of this chapter.
Continued professional growth requires that the profession address some of the concerns and issues that may prevent fulfillment of the potential inherent in this area. Specifically, clinical evaluation procedures need to be ecologically appropriate, produce repeatable and reliable results, discriminate performance levels, be readily available and not cost prohibitive, and be practical for implementation in most clinical practice facilities. If such evaluation procedures are produced, these procedures must have sound scientific validity demonstrated by controlled studies. If this can be achieved, sports vision skill assessment may become a common aspect of patient care.
Similarly, visual performance training procedures need a degree of validation to engender broader acceptance. Some of the same desirable characteristics described for evaluation procedures pertain to training procedures as well. Training programs should attempt to demonstrate vision skill improvement with relevant laboratory and clinical research. The improvement of vision skill performance should also be correlated to a concurrent improvement in sports performance, if possible. However, isolating one area of intervention as being solely responsible for changes in performance is incredibly difficult. This is true for any area of sports training, including strength training, conditioning, speed and agility training, nutritional regimens, and sports psychology. If the improvement of obviously important vision skills is evident from well-controlled research, the transfer to sports performance offers a logical correlation that perhaps would be more readily accepted than only anecdotal reports.
Sports vision specialists have tremendous potential to provide consultation services. The vision factors that influence perception are generally not calculated in the development of sports products. The sports vision specialist is in a unique position to facilitate product innovation in a potentially unique direction. The sports vision specialist can provide scientifically supported advice in areas such as the selection of product colors, the optical properties of performance eyewear, the engineering of performance tints, and the desirable properties of contact lenses for athletes. These potential opportunities could yield fulfilling professional experiences for the practitioner.
The author hopes that, in some small way, this book will help increase the provision of sports vision services to athletic patients and stimulate interest in elevating the professional development of sports vision. Eye care practitioners have the potential to contribute to the performance of their athletic patients; ultimately, sports vision care can contribute to elevating human potential.