PHOENIX, ARIZONA— Professional athletes are generally expected to be in excellent physical condition but some sports also require players with perfect eyesight. Baseball players have some of the best vision in the world and scientists are documenting how having a good eye can lead to winning games.
The 2014 Major League Baseball season begins later this month in the United States. At the Cleveland Indians training camp in Phoenix, Arizona, outfielder Luigi Rodriguez finds hitting a baseball requires focus.
"The ball is a little small, so you have to have good eyes," Rodriguez said. "I'm looking at the ball, I look at the pitcher's arms, to see where the ball gets thrown."
To see it all and process what they see quickly requires excellent vision.
"The normal average person can see something from three meters, where the baseball player can see from 6 meters," said ophthalmologist Daniel Laby. "They can see twice as far away and still see the same target."
Laby is a pioneer in the science of sports vision. Along with his colleague, optometrist David Kirschen, they've published scientific papers on everything from major league vision, to the eyesight of Olympians.
"We've had the opportunity to study the vision in several sports," Kirschen said. "And it turns out it's a key component in some sports and not as important in others."
For example, athletes don't need amazing sight to dribble a basketball, or to throw a punch.
"So if you think about a boxer, it's not necessarily important for them to have 20-20 vision," Kirschen said. "They need to move two hands very rapidly."
Quick response is key in most sports. But to hit a small, fast ball, great eyesight is fundamental.
"This will apply to cricket, and it's going to apply to tennis," Laby said. "And it applies really to hockey. Any fast-moving target sport."
With baseball, for example, Laby says the batter has less than 1/10th of a second to react once a pitch is thrown.
"That's probably somewhere in the range of time they have to see the ball," Laby said. "Just when it's released from the pitcher's hands, they have to see the spin of the seams. And based on that spin pattern, they know what pitch it is. When you know what pitch it is, you know where it's going to come. Once you know where it's going to come, you can put the bat in the right place to make a good hit."
Batters work hard to improve judgment and reaction time, but to sharpen their natural vision, Laby and Kirschen often recommend corrective contact lenses. The goal is to boost normal eyes into the super eyes needed for major league success. Like many of his teammates, Cleveland Indian player Jake Lowery wears contact lenses.
"It helps me see the pitches, see the seams on the ball, keep the brightness down when the sun is out," Lowery said.
To refine his prescription, the doctors ask Lowery to read a standard vision chart. However, identifying black letters on a white background checks focus, but nothing else. To track how quickly players react to more challenging targets, Laby and Kirschen have designed a test where a tiny and often faint letter "C" flashes on a computer screen, sometimes backwards or upside down. The athletes sit 5 meters away.
"It's very very fast, very very faint," Laby said, "and for me as an eye doctor, very difficult to see. But the baseball players seem to see all of these."
Laby says the test might provide a better assessment for people taking driving tests, and could also help budding baseball players, like 9-year-old Matthew, who came to training camp to watch batting practice and dreams of becoming a professional baseball player when he grows up.
Laby says Matthew has a better chance of realizing his dream if his parents get his eyesight checked.
"If you have a young child who's interested in playing baseball, and they just don't see well enough, then the coach won't spend as much time with that player," Laby said.
He says testing eyesight, and getting people the correction they need, can help everyone do better at their game…whatever it is.