October 1, 2008 Optometrists are using a variety of tools to assess visual perception and to help athletes fine tune their visual perception, in a manner similar to how individuals work out to improve strength and agility. Training exercises include tracking fast-moving lights, tapping sections of a peg board when they light up, and more. Training can be tailored to specific attributes vital in certain sports, or even for specialized tasks within a game. For example, baseball infielders and outfielders might be given different exercises.
To the average person, 20-20 vision is just fine -- but for athletes to succeed, their vision must be much sharper. That's why many are turning to sports vision therapy to stay on top of their game.
For athletes to win, they've got to keep their eye on ball. "The average baseball player's eyesight tests at 20 over 12.5," says Kevin Gee, O.D., an optometrist at the University of Houston's Eye Institute in Houston, Texas.
Many don't know maintaining that sharp vision takes work. "You go and you lift all day long, and you can go and get the most expensive bat out there, [but] it's not going to do you any good if you don't have good vision," Dr. Gee says.
That's why Dr. Gee uses sports vision therapy to help athletes at the University of Houston. It's a workout for the eyes that's just as intense as a workout on the field. "You leave very, not only mentally, but physically tired from it," says Kyla Holas, the head coach of the University of Houston's softball team. "Your eye is a muscle just like everything else in your body."
In the workout, peripheral vision and hand-eye coordination are tested on a peg board. Reaction time is tested by fast-moving lights.
"As the lights light up down the track, we are able to track the vision of the players and give them feedback," Dr. Gee says.
Since each player holds a different position on the field, each test and workout can be customized; and it's not just the pro who can benefit from sports vision therapy.
"Whether it be your weekend golfer, or your runner, or the next 'A-Rod' who is in little league, this will definitely help the average person -- because the average person is involved in sports in some way or another," Dr. Gee says.
Holas says her team has improved since starting the program. Along with gaining team spirit and hard work, they ended the season 54 to 11 -- beating last year's season of 44 and 18.
"The details are what separates the great athletes from the average any jump," Holas says.
Dr. Gee says if you are interested in finding a sports vision clinic for yourself, look for a place that has a licensed optometrist on-site.
ABOUT PERIPHERAL VISION: Peripheral vision refers to what we can see out of the corners of our eyes. The retina contains light-sensitive cells called rods and cones. The cones sense color and are found mostly in the central region of the retina. When you see something out of the corner of your eye, the image focuses on the periphery of the retina, where there are very few cones, so it's difficult to distinguish the colors of objects. Rods also become less densely packed toward the outer edges of the retina, reducing your ability to resolve the shapes of objects at the periphery. But our peripheral vision is highly sensitive to motion, probably because it was a useful adaptation to spot potential predators in the earlier stages of human evolution.
HOW WE SEE "DEPTH": The human visual system is designed to allow us to detect fine detail, track a moving object, see colors, and perceive depth. All these components of a visual scene are processed and merged by the brain so that we observe them as one visual experience. How we recognize that different objects are at different distances from us depends on visual cues. For objects beyond 100 feet, the image that's projected on to the back of the eye is basically the same size to both eyes, so cues of depth perception would include knowing the relative range of sizes of objects in general. If one object partly hides another, we know that the object in front is closer. And as we move our heads and bodies, nearby objects will seem to move more quickly than distant objects, an effect called motion parallax.
For objects closer than 100 feet, we need three-dimensional vision. Because the eyes are separated by about six centimeters, each eye gets a slightly different view of the same object. When we fixate on one object, we can tell if another object is in front of or behind it, because the object is located in two different places on the images that reach the retinas, or backs of the eyes. This is called disparity. Experiments have found that depth perception likely occurs in the primary visual cortex, where individual neurons receiving input from the retinas of the two eyes fire specifically when retinal disparity exists.
Editor's Note: This article is not intended to provide medical advice, diagnosis or treatment.