The author has collaborated with his associate, Dr. Gary Polan, OD many times. Dr. Polan has been a pioneer in the field of Sports Vision Training (SVT) and Vision Training (VT) since 1984 (*). In 1996, Dr. Polan's work received corroboration by the staff at the Jules Stein Eye Institute at the UCLA Medical School (**). In this article we outline all the individual skills required by the visual system to perform at its peak that now form the science of VT and SVT.
Dr. Polan's experience in training and improvement of visual skills has replied in “surprising” advances in most learning disabled cases. Improvements in intellectual activity which are generally unexpected, but very welcomed by parents, have not been well documented by rigid research designs to date. Still, we are confident that VT and SVT can play a significant role in improving reading skills, Attention Deficit Disorder (ADD), and Dyslexia.
Few realize that reading is a motor activity like sports! Just one of many common reading flaws is transposing letters like “ea” to “ae”. When the number or severity of flaws effects performance or comprehension, VT or SVT is warranted.
So, before any improvement in reading or athletic performance can take place the visual system must be engaged. What are the exact skills that the eyes posses that can influence performance?
Introduction to Visual Skills
First, readers of this article should realize that ALL visual skills are learned. From infancy, the vision skills that we take for granted, have been built gradually over time. Contrary to folklore, they are not necessarily genetically predetermined and can be improved.
Fact: visual skills, no matter how polished by our activities or sports, can be improved in a clinical or private practice setting. Sports careers worth millions of dollars can be improved and lengthened past their usual expirations. One of Dr. Polan's more famous patients, Olympic track star Carl Lewis, says that “more of his records would still be standing today had I practiced SVT during my competitive career.”
Visual skills can be divided into 3 sub areas: Visual Acuity, Visual Efficacy, and Visual Processing. Visual Acuity is measured by standard optometric tests commonly used for eye prescriptions including standard eye chart examinations.
Visual Efficacy can be measured by testing among the 24 areas listed below which include focusing, convergence, divergence, etc. Visual Processing can be evaluated by tests which measure the extent of learning disabilities such as Reading Disorders, Attention Deficit Disorder (ADD), and Dyslexia as found in items 2, 7, 15, 16, 18, 20, 21, 22, and 24 Most ADD and Dyslexia is responsive to treatments for visual / perceptual deficiencies in these areas of training thus, often diminished or alleviated completely.
Visual Efficacy Skills
All movement mechanisms during sports and reading are enhanced by eye skills and eye health. In turn, improvements in several areas of eye skills will enhance eye performance during motor activity.
For example, reaction time is first dependent on the visual accuracy and recognition skills listed. Here is a brief review of each eye skill which can positively effect motor performance, some related to our experience in tennis. Please note that Visual Efficacy Skills are a subset of all the eye skills listed below.
1) Visual Acuity-your ability to achieve a sharp resolution of an image that can be divided into static acuity (stationary images) and dynamic acuity (resolution of images in motion).
a) Static Visual Acuity-Corrected or not, your eyes should have 20/15 vision for high-speed activities. “20/15” vision means that is you see at 20 feet what the average person only sees accurately at 15 feet away.
b) Dynamic Visual Acuity-the ability to see sharply while the player, opponent, and ball are all in motion. This ability is made up of many other skills such as Convergence, Focusing, Tracking, and Interpretation, etc. Following the action with the eyes rather than the head or body is more efficient and puts less stress on the balance and muscular-nervous system.
2) Visualization-is the ability to plan, imagine, and prepare for upcoming motor skills and movements. Some sports scientists believe visualization of needed skills is more efficient than coaching “pep talks”.
The most famous example of this comes from downhill ski racing. Often the athlete is seen, eye closed and head weaving, picturing the course and its demands in their imagination before the actual race.
3) Peripheral Vision-is critical to awareness of other important things while watching the ball such as your teams, boundaries, or opponents.
4) Depth Perception-is the ability to quickly and accurately judge the distance between yourself and your opponent, teams, targets, and boundary lines while judging the speed, rotation, and flight path of the ball.
Billy J King rates this above court speed and eye-hand coordination for junior tennis players. Quickly eliminated by those who stare during the day-students, programmers, and executives may play poorer tennis during the week than week end for this reason.
5) Visual Pursuit-is the ability to use the eyes to follow a moving object smoothly and accurately. This critical skill is based on good eye teaming and eye muscle balance but it can not track a ball smoothly at high speeds where Saccadic Movement takes over.
Saccadic Movement-is the ability of the eyes to “jump” from one point to another when sessions exceed those of visual pursuit. This skill is used in reading to jump from one word to the next. If this skill is poor, reading ability is affected!
Quick, accurate saccades are used to survey quickly with as little head movement as necessary. Head movement is a less efficient method of eye tracking and can confuse balance. Unnecessary head movements and eyelid reflexes to flinch must be overcome with training.
7) Visual Concentration-describes the cooperation between Visual Pursuit, Saccadic Movement, and Visualization in the “minds eye”, or imagination. This skill is not scientifically well defined yet, but is exemplified by tennis players who must switch concentration rapidly from target, to ball, to processes of planning and prediction which are critical to performance.
8) Speed Of Focusing-is the ability to shift focus from near, intermediate, and far distance. This eye muscle skill is subject to the same fatigue which affects other muscles over the course of exercise.
9) Glare Recovery Speed-is the ability to see clearly after looking toward intense light. Focusing near sun and at tennis court lights causes “dazzle” to the retina.
10) Sight in dim illumination.
11) Eye Muscle Stamina-is the ability to withstand fatigue without decreased performance in a variety of eye tasks. We believe that Shaquille O'neal is the most famous example of this (see 16b).
12) Color Perception-is not critical but may play a role in yellow against white line calls.
13) Eye Dominance-is the ability of the sight in one eye to dominate images from the other. Tennis players generally prefer strokes on the same side as the dominant eye which is usually the right for right-handers over 80% of the time.
14) Fixation Ability-is the skill of preventing eye fatigue which comes from staring at objects too long. Receivers with poor fixing skills fatigue within a few seconds of staring at the server. Other players do not, but staring should be avoided.
15) Visual Memory-is the accumulation of past experiences such as the number of proper swings logged in a players “motor program file”. This combined with visualization for future swings is probably a major factor in consistency during competition. Visual memory fades with time.
16) Spatial Localization-is knowing your position relative to other objects especially while you, ball, and opponent are moving.
a) Esophoria-players who see the world CLOSER than reality, tend to hit / throw shooter.
b) Exophoria-players who see the world FARTHER than reality, tend to hit / throw longer. We believe that Shaquille O'neal is an example of this because he more often hit the heel of the basket towards the end of a game.
17a) Speed of Recognition Time-is how fast you can you identify images.
17b) How fast can you react to those images.
18) Eyes to Body Coordination-is the ability to integrate what you see into an appropriate and coordinated response from your body parts (aka: Visual / Motor Integration).
19) Contrast Sensitivity-is the ability to pick out an important object against a field of other objects.
20) Visual Attention-is the skill used to prepare the eyes and brain which heightens its readiness for an upcoming task. This is a precursor to Visual / Motor Organization. Of course, the body can influence this system which is one reason why elite tennis players bounce during the opponents contact.
21) Figure / Ground-is the ability to pick out an object in the foreground against a variety of background fields; to discriminate the figure to be attended to and to see the interrelationships to its background information.
22) Visual / Motor Organization-is the regulation and organization of motor skills; to choose from a “catalog” of motor programs for meaningful and productive action.
23) Jump Duction-is the ability to move from visual tasks that require convergence to divergence of the eyes and back. Jump Duction deals with vergence; the activity of the extraocular muscles to diverge for distance, and converge for near objects rapidly and efficiently.
24) Auditory / Tachistoscopic Skills- are those which help sound and sight skills complement each other during visual processing. It is the auditory / visual integration ability of an individual which coordinates inputs into a meaningful perception and to shift priority and attention from one sense to the other when necessary. Years ago, preventing air traffic over the US Open tennis tournament in New York was initiated for this reason. Players have to hear the serve as well as see it.
Audition specialists can better assess the ability to discern background from foreground sounds similar to the way we will assess background to foreground objects. This is an area worth of much more study. There is much potential to design audio triggers, cues, and scoring tones for training here. Consider the bell for a horse race!
The “Visual Skills” list above numbers 1-24 is Copyright (c) Jonathan Bailin, Ph.D. 1997.
* Hoflinan, L., Polan, G., Powell, J. “The relationship of contrast sensitivity functions to sports vision”, Journal of the American Optometric Association, 55: 10,747-752, Oct 1984.
** Laby, Rosenbaum, Kirschen, Davidson, Rosenbaum, Strasser, Mellman “The visual function of professional baseball players”, American Journal of Opthalmology 122: 4,476-485. Oct. 1996.