In addition to blink-controls for phones or pocket computers, the patent application describes ways to embed minute cameras within the lenses along with circuitry to process the image data and send it via wireless network to one or more remote devices.
The camera would be able to track movements of the eye and record images only of objects on which the user focused.
Google's patent applications said the contacts would have several sensors that would detect eye blinks separately in each eye and track them as input or controls similar to the blink-control system Google is developing for Google Glass.
The sensors would include a photodiode that could detect changes in light when eyes were open or closed, a pressure sensor to detect movement of eyes or eyelids, a conductivity sensor that responds to changes in the volume or makeup of tears, a temperature sensor, and an electric field sensor.
The patent says the lenses can be powered by batteries or any other suitable power source, but are likely to be powered wirelessly using the same transceiver that would allow it communicate with an Android phone or other device. Adding a camera would make the lenses -- like Google Glass -- able to take pictures that would be sent to and posted online by a user's Android device.
This would also allow images to be sent in real time to a phone or belt-top computer that could interpret and describe them audibly, giving blind or vision-impaired users visual guidance using their own eyes to provide the angle of view, if not the imagery.
Google noted the camera's ability to detect faces as well as other images, which could help the blind recognize acquaintances, or help police or anyone else needing to put a name to a face.
A camera in a contact lens could have many other uses, too, of course, including secretly taking pictures or video -- though the "secret" part would only work if the contacts were a lot less obvious than the chunky Google Glass, wearers of which have been attacked in San Francisco twice in the past two months.
In addition to contact lenses and other wearable devices, Google has already advanced its autonomous car development project to the point that it was able to present data in October showing Google cars steered and accelerated more smoothly than humans.
Ninety percent of new vehicles will ship with connections to wearable computers by 2019, according to a report from ABI Research, but carmakers aren't the only industry interested in human-machine interfaces (HMI).
There has to be some way to tell autonomous cars where to go, however, which is where the in-vehicle gesture system Google patented in 2013 would come in.