The application, originally filed by Google in August 2011, goes into deep detail on how the glasses could be constructed, with long sections describing factors seemingly as mundane as the arms and bridge of the glasses frames.
As for the display, in a section of the application labeled "Background," Google explains that some head-mounted displays can "almost entirely obstruct the wearer's vision outside of the screen." Others can be "heads-up displays" where an image is displayed on, in, or through a transparent display that superimposes the displayed image over the surrounding environment. Google cautions, though, that the heads-up display can have many limitations, including fit and comfort to the wearers, as well as limited functionality.
The company notes that both head-mounted and heads-up display gadgets can be "passive" and deliver things like video and audio tracks from outside sources, like cell phones or tablets. However, it noted that those would have limited functionality. Accordingly, Google argued that "further advances in wearable devices including displays have been needed," hence its push in the area.
There's too much detail for CNET to include all of it here, and it's unlikely that Google will implement all of the items described in its application. But in the competitive (and litigious) world of patents, Google likely wants to be safe to create anything it desires related to the area.
CNET's Josh Lowensohn contributed to this report.