Sports Vision Training

Introduction

Baseball is a sport with a tremendous amount of quantitative batting data being generated from batting averages, slugging percentages, and numbers of hits, walks, strike outs and a host of others. In particular, batting is an activity that has rigorous demands for eye-hand coordination requiring concentration and good visual acuity as well as depth perception. There is general agreement that vision training is beneficial to various sports related activities but an objective and quantifiable assessment validating the concept is relatively lacking in the literature [1]. The time it takes for a pitched ball to reach the plate is approximately 0.4 seconds. In that time the batter needs to spot the pitch, assess rotation and direction of the ball to finally make a decision to swing or not [2]. When swinging the bat the batter must consider both the timing of the swing and the angle of the swing. The swing takes approximately 0.2 seconds [3]. With the velocity of action potentials being approximately 60 m/s and approximately 2 mS needed to cross each synapse, and a minimum of 5 synapses crossed that means it can take as long as 0.03 seconds to process the swing. Therefore, there remains only about 0.17 seconds to decide to swing. As a physical activity batting is ideal for assessing and quantifying the benefits and affects of high performance vision training.

The Research

This program was designed for the University of Cincinnati baseball team and was reviewed by Institutional Review Board and was compliant with all human subjects rules. Similar programs have been developed by Nike Sparq system. Three times a week they performed two one minute sessions on the athletes. The reason for doing multiple sessions is to demonstrate consistency and improvement with the tests. The staged and progressive nature of the tests also helps keep the athletes engaged. Tachistoscope, Brock String, Eyeport, Rotary, Strobe Glasses, Near Far Training, and Saccades.

Dynavision

The Dynavision is a eye-hand coordination device that tests and improves visual motor skills . The off the shelf, *A training session is an established Dynavision protocol . It uses traditional eye-hand reaction training to assess visual fields and improve reaction times. This training drill takes one minute. The result is a number of hits in one minute as well as the average reaction time for each hit.

Tachistoscope

The Tachistoscope is a device that trains the brain to recognize images faster, and loosely correlates to batting average [8]. We flash numbers on a screen, typically starting with 1 number at 0.25 seconds, gradually adding more numbers [up to 4] randomly placed on the screen, and also including different backgrounds at increasingly faster flashes. We also start with simple contrasts such as black on white and make them increasingly more difficult such as darker green letters on a lighter green background. This is called contrast sensitivity and is very effective in training an athlete to recognize objects in his visual field faster.

Brock String

The Brock string is a classic visual training aid that uses a string and colored balls [5]. Ours was an eight foot string with 5 colored balls. Typically the athlete would have the nearest end of the string by their nose and have it extend away from them parallel to the ground. The athlete needs to focus on the balls, set along the 8” string, back and forth for 1 minute. This requires adaption and convergence of the eyes to find and focus on the balls. The exercise conditions the eye and lens muscles to quickly make adjustments.

Rotary

The rotary (Bernell Corporation of Mishawaka, IN) is a vision pursuit device that has letters and numbers attached by Velcro. It rotates at increasing speed as the athlete improves the ability to call out and point the laser pointer at the appropriate letter/number in alphabetical/numerical order. This is done for 1 minute both clockwise and counterclockwise.

Strobe Glasses

Strobe glasses are LED lenses that flash and completely block the signal to the eyes as objects are in motion [5]. They are set to flash more rapidly in the initial training stages and are gradually slowed up as the athlete gets adapted to the training. The slower the interval, the more difficult the task due to less visual input due to the LED’s interruptions. The brain is forced to visualize where the pitch is going by processing the information it gets from the eyes faster. It is used for batting practice and the effect is that batters report that the pitch seems to be moving slower and they can pick up the ball coming out of the pitchers hand easier.

Saccades

Saccades are rapid movement of both eyes in the same direction from one object to another voluntarily [5]. We set charts of random letters on a wall, both horizontally and vertically and had the players stand at varying distances and focus from one chart to another, calling out the letters they see in order on a line, alternating from one chart to another for a period of 1 minute. This is done in many forms such as looking over and alternating shoulders after looking forward at another chart. This simulates a fielder chasing a hit ball.

Near Far Training

Near far training consists of the subject focusing on two different cards approximately 18 inches and 10 feet away [5]. The athletes focus back and forth on the card and count how many iterations they can do. The cards have rows of random letters so that they have to track their progress in a similar fashion to the Saccades.