Optometry and Vision Science, Pacific University
Competitive athletes are continuously searching for ways to improve their performance in their sport. Most of the training focus is on the development of core physical abilities, such as strength, speed, agility, and endurance. The other major focus is on skill development for specific sport applications, often requiring significant repetition with feedback to develop optimal biomechanics. However, visual performance is an important factor that can often be overlooked when it comes to training regimens.
Visual Performance Assessments
The role of visual performance in sports has received a fair amount of attention over the years. There are several ways to assess vision and visual processing abilities and to train for improved vision, but many athletes have limited access to evaluation and enhancement approaches. Visual demands can vary tremendously between sports and even positions, so a thorough visual task analysis should be conducted to help identify what vision factors would benefit the most from enhancement.
The vision and perceptual skills often identified as important for sports include static and dynamic visual acuities, contrast sensitivity, stereopsis, accommodative-vergence facility, span of perception, multiple object tracking, central and peripheral eye-hand/foot response speed. Some aspects of these visual skills are assessed as part of a routine vision exam, but many are not evaluated. It is helpful to classify the areas of assessment to better understand how the factors affect performance.
The Welford Information Processing Model is useful for understanding how the critical sporting action output results from the successful execution of lower-level processes. Using this model, the following is an example of classifying assessments into the relevant perceptual mechanism:
- Perceptual Mechanism
- Visual Acuity
- Contrast Sensitivity
- Dynamic Visual Acuity
- Ocular Alignment
- Stereopsis
- Accommodative Function
- Vergence Function
- Oculomotor Function
- Peripheral Vision
- Decision Mechanism
- Speed/Span of Recognition
- Multiple Object Tracking
- Visual Attention/Visualization
- Effector Mechanism
- Central Visual-Motor Reaction Speed (Eye-Hand, Eye-Foot)
- Peripheral Vision Response Speed
- Vision & Balance
- Coincidence-Anticipation timing
Visual Performance Training
The goals of sports vision training are to remediate any vision conditions that may limit performance, such as refractive error, and to enhance an athlete’s visual performance factors when they are less developed than their peers. The most common options to optimize visual performance include refractive compensation, filters, nutrition, and sports vision training (SVT). 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 are different approaches to developing effective SVT programs. Component skill training approaches isolate specific vision performance skills to be enhanced with targeted procedures, including digital visual training instruments. While these digital platforms are effective at improving specific visual factors, naturalistic training approaches provide a platform to apply the training directly to the sport. Digital technologies, such as stroboscopic training, have developed to allow SVT approaches to be used during natural training activities. Other options include virtual reality simulations that can recreate sport scenarios to promote sports-specific visual-cognitive abilities.
Nutritional Improvements for Better Visual Performance
on eye health and visual performance has not been well understood. Recently, there has been significant placebo controlled, double-bind research on the effects of specific nutrients on visual performance in young, healthy people. Lutein (L) and zeaxanthin (Z) are plant-derived carotenoids that are found to be concentrated in the eye and brain. L & Z are the only two naturally occurring carotenoids found in the macula and concentrated within the inner layers of the fovea (macular pigment) to act as a filter for light.
Since the dietary intake of important nutrients is a modifiable factor, increasing the intake of L & Z may provide valuable improvements to visual neural function that can benefit athletes, including:
- Glare recovery and discomfort
- Photostress recovery
- Contrast sensitivity
- Visual acuity
- Visual processing speeds
- Reaction time
- Blue light protection
Athletic Application
What do these improvements look like for athletes? Improved glare recovery and reduced discomfort helps a football player find the long pass after it passes through stadium lights to make the catch. Photostress recovery helps a baseball player exiting the dark dugout see “normal” faster after experiencing the blinded feeling when stepping into the sunlight. Contrast sensitivity helps a golfer locate his ball in the air after a drive. Visual acuity helps a sharpshooter identify the target quicker and more accurately. Visual processing speeds and reaction time speeds up the time it takes athletes to read a situation, make an informed decision, and physically react. Blue light protection helps a gamer’s eyes feel less tired and strained during a long campaign.
Increasing macular pigment through L & Z supplementation offers a potential method to improve visual performance by enriching natural physiology. Further, common symptoms following traumatic brain injury include increased sensitivity to bright light (glare discomfort), glare disability, and slowed photostress recovery. Supplementation with L & Z may provide similar benefits to filter application in athletes who have concussion-related symptoms and may provide more long-term relief.
Athletes should be counseled on the time course for the effects of supplementation. The protective effects of L & Z are fairly immediate, but the visual and neural benefits will take longer for the macular pigment to accumulate. As a general guide, the visual benefits will take one to two months, and the neural benefits will need three to four months to become noticeable.
Dr. Erickson 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 Sports Performance, 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 is a member of the EyePromise Scientific Advisory Board. EyePromise provides unmatched expertise in nutrition science and is the leading provider of nutritional supplements that support eye health.