Google got a patent on its “gaze” tracking technique last week. It is intended to be used with a head-mounted device - such as Google Glass - which then communicates to a server, allowing Google to create “pay-per-gaze” that would register whether the person has looked at an ad. It would then charge the brand, like a “cost-per-click.” The patent application, which was filed back in 2011 but only recently awarded, according to Phys.org, also says the technology could infer “emotional state information” by measuring a user’s pupil dilation.