There have been some guides on 3d printing DIY eyeglasses in the past but Jenny made a dedicated Blender library that will enable you to create high quality 3d printable frames from SVG (scalable vector graphics) images of commercial glass frames.
The library will allow you to adjust all the parameters to get a perfect fitting frames where you can insert your prescription lenses.
Here is a video of how you insert the lenses in a frames designed with this method:
She made two post detailing the process:
You can download her eyeglasses Blender library here:
Great work Jenny! As a life long glasses wearer I salute you!