The evolution of Google Glass
The six images (that the search giant posted on Google Plus) depict how Glass went from a bulky Frankenstein of a machine to the elegant frame that you know now. Google actually claims it took it two years of iterations on design to arrive at the final one.
It seems that some key elements of Glass were there from the get-go: things like the touchpad on the frame on the right, the unique Prism projector display and the built-in camera are on all of the prototypes. At the same time, there is one part that changes hugely with almost every protototype, and it is the frame, of course.
We can only guess how the further evolution of Glass will go. Right now, the biggest question regarding the ambitious Google project is when (and whether) it’d launch, and at what price. We've earlier heard speculations about a $600 starting price, and if we had to guess about a Google Glass release date, we'd say Google I/O this summer. What do you think: is Glass coming to store shelves soon, and do you want it to?
source: Project Glass