Google’s plan to bring smart contact lenses to diabetes sufferers inched closer to reality as the company secured two patents last week for the cutting edge, biometric sensor technology.

Known among scientists as “Ophthalmic Electrochemical Sensors,” these contact lenses will feature flexible electronics that include sensors and an antenna. The sensors are designed to read chemicals in the tear fluid of the wearer’s eye and alert her, possibly through a little embedded LED light, when her blood sugar falls to dangerous levels.

According to the patent:

“Human tear fluid contains a variety of inorganic electrolytes (e.g., Ca.sup.2+, Mg.sup.2+, Cl.sup.-), organic solutes (e.g., glucose, lactate, etc.), proteins, and lipids. A contact lens with one or more sensors that can measure one or more of these components provides a convenient, non-invasive platform to diagnose or monitor health related problems. An example is a glucose sensing contact lens that can potentially be used for diabetic patients to monitor and control their blood glucose level.

Google’s project is one of a number of in-eye wearable sensor technologies currently under development at universities and research facilities around the country. However, with two patents in hand Google’s project may have a leg up on the competition.

This side view of the smart lens show the polymeric material and the embedded substrate (230). Image: Google

The patents also offer a rare opportunity to see how Google and its research partners envision the Smart Contact lens fitting on the human eye.

For example, Google intends to both communicate and power the electronics-embedded contact lens with a pair of antennas, though the patent notes that these two functions could be embedded within one antenna.

These images show how the lens would sit on the human eye (10) and how the eyelids (30 and 32) would close over it. When the lids distribute tears over the eye, they will also, by design, coat both the convex and concave surface of the smart lens. Image: Google

As for how the eye can see past the thinner-than-a-strand-of-hair electronics, the patent notes that the substrate is too close to the eye to be in focus and it’s positioned away from the center of the eye and, thereby, away from where light is transmitted to the retina. It also notes that the substrate can be made of transparent (read: “see-through”) materials.

Google, which announced the project in January, still has to get FDA approval before anyone starts wearing smart contact lenses. Still, it’s clear that glucose level detection is merely scratching the surface of the potential for these lenses. If Google can effectively build free-standing, communication-ready electronics in a transparent device roughly the size of a standard contact lens, there’s no telling what other kinds of smarts the lens will eventually be able to support. Could Google Glass Contact Lenses be far behind?

It's still unclear how long before Google plans on commercializing the smart contact lens research project. Mashable has contacted Google and will update this story with its comments.