Google is developing "smart" contact lenses it says would help diabetes patients be able to monitor their glucose levels without needing to prick their fingers, the Associated Press reported on Thursday.

The device contains thousands of small transistors and uses tears to gauge a diabetic's glucose levels, and was conceived at the company's "Google X" lab.

"It doesn't look like much, but it was a crazy amount of work to get everything so very small," researcher Brian Otis told the AP.

USA Today reported that the prototype lenses can deliver a glucose reading once per second, with the sensor and a tiny chip built between two levels of lens material, with a pinhole in the lens allowing tear fluid to make its way toward the sensor.

"We wondered if miniaturized electronics -- think chips and sensors so small they look like bits of glitter, and an antenna thinner than a human hair -- might be a way to crack the mystery of tear glucose and measure it with greater accuracy," Google said in a statement.

Normally, diabetics check their glucose by pricking their fingers or through a needle embedded in their stomach. The AP reported that the market for monitoring devices should be worth $16 billion by the end of 2014.

"This has the potential to be a real game changer," researcher John Buse said of Google's prototype. "But the devil is in the details."

Watch the AP's report on Google's new lenses, as posted online on Thursday, below.