This project contains a source file that you can print to a 3D printer. The part you make can be used to mount a lens on Google Glass. The Instrucable also lets you choose the right lens.
Mounting a fixed lens fixes a few problems for me with Google Glass. My right eye (the one who sees the Google Glass display) is very nearsighted. Therefore, the display of Google Glass was too blurry for me to read, as the optics see a wider screen at a distance of about 8 to 10 feet. It should also solve the problem for people whose right eye is too provident. I normally do not wear glasses because my left eye is not myopic.
I found that when I wear Google Glass, others often want to give it a try. The assembly is very easy to remove, so it is easy to let others do a test.