One of the advantages of the eye fluid monitor is that it provides a continuous reading, "as opposed to a prick, which only tells you what it is when you prick," said Powers. "Blood glucose is labile and changes in a matter of minutes."
The subcutaneous device is implanted under the skin with a needle.
"It's not as easy as putting it in a contact lens," he said. A smart lens could perhaps equilibrate quickly -- "not seconds, but probably minutes ... and it could potentially be faster than subcutaneous glucose."
But blood glucose can rise or fall quickly, said Powers, and "just how faithfully [a smart lens] does that when there is a blood glucose change, that has to be worked out."
"[Google] would have to prove that the eye fluid would equilibrate with the blood and have the same dynamic," he said. "But it's too early to tell if one is better than the other."
And, he cautioned, there is "more than a little work to be done" before the Google [x] lens can be used clinically. "There are still a number of issues using the glucose sensors and adapting them. It will take some validation studies."