The lens is built more for diabetic individuals than anything else, using a wireless chip and miniaturized glucose sensor that are embedded between two layers of soft contact lens material. Google's current prototypes can "generate a reading once per second," and it's also exploring the integration of "tiny LED lights that could light up to indicate that glucose levels have crossed above or below certain thresholds." The company admits that it's still very early for the tech, and it is only in initial talks with the FDA in order to get clearance to sell it.
That said, it's obvious that there's something to the project, unlike a similar Microsoft vision that has gone nowhere since surfacing quietly a few years ago. The idea of adding a computer to a contact lens isn't exactly novel, but getting this close to market hasn't happened at any time prior. If there's one thing that's becoming ever clearer, it's that Google is diversifying mightily. A search company? Pssh. This is a conglomerate, not even 20 years old.