Google already has a patent that would let Glass and other eyewear identify what's in front of you. However, it just received a new patent for a method that could follow your exact gaze. The proposed system would include both forward-facing and eye-tracking cameras, correlating both to determine what's grabbing your attention. It could even gauge emotional responses to objects by watching for pupil dilation, and could be used to charge advertisers based on how long wearers stare at a given ad. While there's no guarantee that Google will ever use the technology, the company has also received another patent for a quantum dot-based eye display -- it's clear that Google isn't treating these ideas as afterthoughts.