I'm not a 3d expert, I dont have a printer yet only a partly owned one in the uk, so i dont know anything about the printing specifics and details to do spectacles, however i am an expert on spectacles with 35 years experience in the business from glazing, dispensing, manufacturing, and buying, an i can make models in ZBRUSH scaled to mm so i think i can help refine your specs.
Thanks to GR5 for directing me to this thread, i would like to create a version of your specs in zbrush with correct temple joints, bump bridge, and base curve on the front, also your old lenses will have a base curve and V bevel on them and the inside rims of your 3d frames will need a Vbevel cut into them to hold the lenses, the normal format to glaze plastic frames with cut lenses is to heat the frame rim plastic and stretch the rims with the lens by pushing it into the rim where it will seat in the V bevel groove, this is not easy to do nd requires practice, the lens size should be around 0.7mm overlapping the frame lens size.
I will make it in three separate parts and recommend sourcing self tapping screws form a local store for assembling the temples to the front.
I will need the measurements of your current lenses (only the A measurement - box size - Horizontal measurement across the furthest most points of one lens including the Vee bevel)
I have taken the image of your old glasses and will make an STL, but i dont know where to post it, i have dropbox so if you supply me an email add i can send you the link,
I am currently making prototype design for various models in ZBRUSH for commercial prototypes but have just had a UM2 delivered in the uk and need to try the process with someone who knows how to print as we are not up to speed yet, so it will be very useful to me also.
OK heres some pictures of the specs in zbrush, let me know if anyone wants the stl, i have yet to convert it but it doesnt take long.
Still have to figure out making a screw and thread, but self tapping small screws are available from hardware stores