Need an excuse to log a few more hours playing Call of Duty or Medal of Honor? Scientists demonstrated improved vision in test subjects after daily doses of first-person shooter games.

Scientists at McMaster University took subjects who, as the result of surgery correcting congenital cataracts, had less than 20/20 vision. Subjects played Medal of Honor for a total of 40 hours over the course of 4 weeks before having their vision retested. The results? The CBC reports:

The participants found improvements in detail, perception of motion and in low contrast settings.

In essence, players could now read about one to one-and-a-half more lines on an optometrist’s eye chart.

“We were thrilled,” Lewis said. “It’s very exciting to open up a new world of hope for these people.”

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