In the last post, Dr. Graham Erickson talked about assessing visual performance and processing and the different ways of doing so. Now, he’ll get into the ways to help athletes enhance their vision and visual processing to better their competitive advantage. Fair warning, this is the longest post in this series. Let’s get started! The most common options considered for optimizing visual performance include:

• Refractive compensation
• Filters
• Nutrition
• Sports vision training (SVT)

The goal of these interventions is to remediate any vision conditions, such as refractive error, and to enhance a patient's or player's visual performance factors when they are less developed than their peers.

Sports Vision Training

Sports vision training programs operate under the logic that practice with demanding visual, perceptual, and sensorimotor tasks will improve vision, leading to:

• Quicker sensory processing
• Swifter and more accurate motor movements
• Improved athletic performance
• A potential reduction in injuries

There is a long history of SVT approaches that isolate component visual performance factors, and repetition of these SVT activities is combined with increasing integration of other sensory and cognitive demands. There is research demonstrating that SVT drills can improve sports-relevant vision or manifests into better on-field performance. ¹ However, isolating one area of intervention as solely responsible for any changes in performance is quite difficult. SVT approaches have advanced greatly because training programs utilize information about the structure and function of the visual system combined with recent innovations in perceptual learning paradigms to create more specific and robust learning. There are many examples of dramatic improvements in visual abilities from appropriately structured tasks, showing that practice leads to substantial gains in sensitivity that can last for months or years. ² Most importantly, this research showed that perceptual learning benefits can transfer to new, untrained contexts.³ Virtual reality simulations have also enhanced SVT by recreating and augmenting sporting contexts to promote certain sports-specific visual-cognitive responses.

Component Skill Training

There are several recent digital visual training instruments that are based on principles of perceptual learning and have shown promise for improving vision and sporting performance. Below are a few examples, and more detailed information can be found in a recently published review paper. ¹

Visual Acuity & Contrast Sensitivity

A recent innovation in visual component training is called Ultimeyes^®. This video application incorporates diverse stimuli, adaptive near-threshold training with learning-optimized flickering stimuli, and multisensory feedback in a digital training program designed to improve foundational aspects of visual sensitivity. In a series of studies, this training app has demonstrated improvements in visual acuity and contrast sensitivity in both nonathletes⁴ and athletes,⁵ as well as improved batting performance in collegiate baseball players.⁵

Multiple Object Tracking

The CogniSense NeuroTracker is an example of a perceptual-cognitive training program. The training platform entails an immersive three-dimensional “multiple object tracking” program to increase cognitive load. There is ample research with the NeuroTracker system involving groups of healthy young adults,⁶ healthy older adults,^7,8 and athletes across several sports and skill levels. NeuroTracker performance has been correlated with actual game performance in professional basketball players.⁹ It’s also demonstrated that training with this program can improve small-sided game performance in university-level soccer players.¹⁰

Visual-Motor Reaction

Visual-motor reaction training is a common aspect of component SVT since many sport situations require an athlete to quickly make motor responses to visual information. Several instruments have been created to evaluate and improve visual-motor reaction speed, including the Dynavision D2^TM, Vision Coach^TM, SVT^TM, Batak^TM, Binovi Touch, Reflexion Edge, and FITLIGHT Trainer^TM. These instruments each consist of a two-dimensional panel or setup with an array of illuminated “buttons”. The athlete is required to press a randomly lit button as rapidly as possible with one hand; then, another button is lit in a random position on the instrument, and the reaction time reflex cycle is repeated for an established period – similar to a Whack-a-Mole game. FITLIGHT ^TM is unique in that it employs wireless LED-powered light units that are controlled by a computer tablet and can be flexibly placed at distances up to 50 yards from the controller rather than embedded in a fixed board. Several studies have utilized the Dynavision tools in SVT programs that include additional SVT procedures and demonstrated improvements in batting averages, slugging percentage, and on-base percentage in baseball.¹¹ In a study with a similar SVT program design, concussion incidences during four years of collegiate football were reduced relative to the previous four years without the training programs (1.4 vs. 9.2 concussions per 100 player season).¹² The visual-motor reaction instruments are most often used to train eye-hand reaction, but there are some instruments that provide a method to train eye-foot response. The Quick Board and FITLIGHT^TM offer training options for foot speed. Training with the Quick Board has demonstrated significant improvements in foot speed, choice reaction, and change-of-direction in moderately active adults.¹³

SVT Systems

In addition to providing a platform for visual performance assessments, a variety of computerized training programs are also available on the Senaptec Sensory Station, RightEye, and Vizual Edge Performance Trainer^®.

Naturalistic & Virtual Reality Training

Actual sports practice is typically viewed as the most naturalistic method for developing the necessary skills for success. However, practices have the potential for injury. Over the past several years, digital technologies have been developed to allow SVT approaches to be used during natural training activities and in virtual reality simulations that can recreate sport scenarios to promote sports-specific visual-cognitive abilities.

Stroboscopic Training

Strobe lights or liquid crystal shutter eyewear can be used in natural practice situations to intermittently disrupt vision, allowing the athlete to see brief snapshots of the activity being performed. This provides a format for training under more challenging visual conditions than typically encountered so athletes learn to use limited visual input more effectively. The most common device used for stroboscopic athletic training has been the Nike Vapor Strobe ^® (Nike Inc, Beaverton, OR) eyewear, but since it has been discontinued, a similar new product is available from Senaptec. These products all use battery-powered liquid crystal filtered lenses that alternate a 100 ms fixed-duration transparent state with complete visibility and a variable-duration opaque state that can be changed through durations ranging from 25-900 ms of visual occlusion. With all strobe training, the difficulty is increased by lengthening the duration of the opaque state. Studies involving stroboscopic training suggest that it can enhance sensory and motor skills, with some evidence that these translate to on-field performance. Stroboscopic training has been shown to increase dynamic visual acuity (after one training session) and ball catching performance (over the course of the training) compared to training without a stroboscopic effect.¹⁵ In a study with National Hockey League players, the strobe training group averaged an 18% improvement in on-ice skill performance from pretraining to post-training, whereas the control group’s performance did not improve.¹⁵ Additionally, a preliminary study suggests that strobe training might be a useful tool for lower extremity (e.g. ACL) injury recovery.¹⁶ The study establishes a link between dynamic movement mechanics, neurocognition, and visual processing, and provides evidence that neurocognitive and visual-motor training approaches during the rehabilitation of ACL injury may further optimize treatment by mitigating post-injury movement dysfunction and reducing injury risk when returning to play.

Virtual Reality Training

Computerized simulations and virtual reality (VR) platforms have been developed to simulate game action and are a type of naturalistic sports training. Such simulation platforms allow for the design of complex training protocols that can mimic real game activities, allowing athletes to gain ‘mental repetitions.’ Three companies in particular, Eon Sports VR, StriVR Labs, and Axon Sports, have recently developed suites of digital training simulations that are marketed towards athletes, coaches, and trainers. With these broad-application platforms, there is a growing number of products that target specific sports. It is important to note that these VR sport simulations are a new technology with relatively little supporting evidence at this time. Read about an unlikely way to improve visual performance in the next post of this series.

Author

Graham Erickson, OD, FAAO, FCOVD has been on the faculty of Pacific University since 1998 and currently teaches the Vision Therapy, Strabismus/Amblyopia, and Sports Vision courses. He has authored the text Sports Vision: Vision Care for the Enhancement of SportsPerformance, as well as co-authoring the text Optometric Management of Reading Dysfunction, and published chapters and articles in various optometric journals. He lectures internationally on the topics of sports vision, pediatrics, and binocular vision. Dr. Erickson published a perspective piece related to nutrition and visual performance in Vision Development & Rehabilitation. Find it on page 221.

References

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