Could a smartphone app improve your eyesight?
17 March 2014 Last updated at 12:10 GMT
A new app called UltimEyes claims it can help users see further and make things sharper by using simple puzzles to activate the visual cortex in the brain.
Users of the app have to click on a series of fuzzy targets which become harder to see as the game progresses.
In a small study, 19 baseball players lengthened the distance they could see clearly after using the app 30 times for 25 minute intervals.
The app's inventor, Aaron Seitz, explained the game required prolonged use to produce a benefit.
"If you really want to get changes that are going to make you be able to see a line or two lower in an eye chart, you really need to work at this," he said.
BBC Click's Jen Copestake reports.