"Smart contact lens." Get used to that term, even if it makes you cringe - a new patent from Google indicates that at least someone at Mountain View thinks it's a potentially viable idea. Patent Bolt reports on a Google application to the USPTO for "multi-sensor contact lenses," intended primarily as a method for blinking input or input augmentation for wearable devices, or just electronics in general. (Note: this shouldn't be confused with Google's other contact lenses, announced in January as a medical diagnostic device for diabetics.)
The basic idea is that a number of sensors embedded into a contact lens could be used to detect blinks with incredible accuracy. The technology to track eyes and blinks already exists, but it's been focused almost exclusively on external cameras. The patent application describes a light sensor, pressure sensor, temperature sensor, and conductivity and electric field sensors, all combined with a control circuit and power source embedded outside the user's physical field of vision. This isn't a "smart" device in the traditional sense - there would be no serious computation going on inside the lens itself - but the sensors could give extremely precise readings on the number and duration of blinks. One of the explicit uses of the sensor is to detect changes in light reception to accurately infer a blink.
To what end? Google's patent application describes input based on a pattern of blinks, both for wearable and non-wearable devices. To put it simply: a user with one of these contact lenses could send commands to a smartphone or Google Glass simply by blinking. "Blink once for yes, twice for no," that sort of thing. Of course, the technical methods and possible uses for this sort of input are far more complex, and so is the terminology in the patent application, because patent lawyers necessarily cover every possible interpretation and application of a theoretical technology. But "blink control" would be a good way of summing up this particular idea.
The patent application was filed in late 2012, which would have been in the latter part of development cycle for the initial release of Google Glass. (The patent describes a contact lens that can connect to a wireless network, and potentially interact with any wireless device.) A few of the more practical parts of the idea are left abstract, particularly the power supply; Google describes various method of power including solar, thermal, or radio frequency power. It's safe to say that any real-world developments of this idea are quite a ways away even now, but the potential for expanding user input is interesting. And a little creepy.
Source: Patent Bolt