I break my glasses frames a lot, they are currently almost half made of glue and varying adhesion products. I designed these so I could just print out new frames or frame pieces whenever I needed to, they are shaped so I can simply pop in my current lenses. These are a work in progress, and now that I have a CAD model of my own glasses I can add space for surface mount electronics, wires, and such.
To make them I taped my current frames to my screen zoomed to a 1:1 ratio, and carefully made a spline of the lens perimeter dimension, then did a bunch of fine tuning with my calipers and the dots consisting of the spline. All the other splines were done visually to my taste, as long as the lens dimensions are good the rest of the glasses can be any shape.
I haven't printed these out yet, but when I do this is my plan. I am going to use a hot air reflow station to heat up the nose bridge and lens areas, then bend them to the same curvature of my current frames by just holding the two parallel to each other. I designed the frames to be just a little bit smaller than in real life to try and accommodate for the geometric stretching they will experience.
To make sure your lenses will fit in the frames print the image out at a 1:1 scale and cut out the interior of the frames, then insert the pieces of paper into your current frames and adjust accordingly.
If your first pair doesn't ft the way you wanted, measure the improper dimensions, update your model, and reprint!
Take heed in the work-in-progress sign. The hinges may need to be beefed, up; I have multiple files ready to go so stay tuned.
If you want the CAD documents for these files give YouMagine some love at https://www.youmagine.com/designs/glasses-frames#!design-information
Detailed information here: http://umforum.ultimaker.com/index.php?/topic/3932-designing-a-new-set-of-glasses-frames/?p=57088