A couple months of game training on a computer or iPad can improve eyesight well beyond normal 20/20 vision.

Baseball players rely on their vision to excel on the field. Now, researchers have found a way for players to take their vision—and their performance—to an entirely new level. And it only takes a couple of months of game training on an iPad or computer.

A new study published Monday in Current Biology, baseball players from the University of California, Riverside (UCR), improved their eyesight by 31 percent on average, compared to players who didn’t use the vision training game. Some of the 19 players in the study even went well beyond normal 20/20 vision.

“The demonstration that seven players reached 20/7.5 acuity—the ability to read text at three times the distance of a normal observer is dramatic,” study author Aaron Seitz, associate professor of psychology at UCR, said in a press release, “and required players to stand forty feet back from the eye chart in order to get a measurement of their vision.”

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During the vision training game, players searched for and chose certain visual patterns on the screen, ones that researchers think the vision center of the brain responds best to. As the game progressed, those patterns dimmed, forcing the players to exercise their vision.

Unlike other programs designed to improve eyesight, this one worked the brain, not the eye muscles, making it brain training as much as vision training.

“The goal of the program is to train the brain to better respond to the inputs that it gets from the eye,” Seitz said. “As with most other aspects of our function, our potential is greater than our normative level of performance. When we go to the gym and exercise, we are able to increase our physical fitness; it’s the same thing with the brain. By exercising our mental processes we can promote our mental fitness.”

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After training 25 minutes a day four days a week for two months, players reported that they could see the ball much better, had greater peripheral vision, and were able to distinguish objects more clearly in dim light conditions, which are common during night or overcast games. The players even said that their eyes felt stronger and didn’t tire as much.

As you might expect in a game where “keep your eye on the ball” is common advice, better vision boosted performance on the field. Players who underwent vision training struck out less and earned more runs, along with other game day enhancements. Based upon these improvements, the researchers estimated that stronger eyesight helped the team win an extra four to five games during the season.

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This isn’t the only study to use vision training to improve the performance of baseball players. Researchers at the University of Cincinnati found that after six weeks of training—coupled with maintenance training during the season—baseball players improved their batting performance by 10 percent or more.

This year, Seitz and his colleagues are testing the benefits of ongoing maintenance, but he said that previous research in perceptual learning—the kind that’s related to the senses—showed that initial effects last at least two years even without further training. In addition, the researchers hope to boost their own performance in the future.

“While we are excited about our initial results,” Seitz said in an email to Healthline, “establishing a complete understanding of what training schedule is most optimal and the long term impacts of the training will take years to figure out.”

While superhuman vision is great for helping baseball players judge whether a ball is in the strike zone, this research has other real-world applications. The researchers will be expanding their work to include other groups, such as police officers and people with low vision due to eye problems like cataracts, lazy eye, or macular degeneration.

For vision problems that stem from the shape of the eye, such as nearsightedness, brain training may help, but is only one piece of the puzzle.

“Really the best solution to good vision is to use lenses or surgery to optimize the optics of the eye and then use brain training to optimize how the brain processes this information,” Seitz said. “Focussing on just one side of the equation will leave us with suboptimal vision.”

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