I remixed this to make the glasses assembleable.  When I tried to assemble the original design, I discovered that the embossed lettering on the bows prevented them from being inserted into the slots they were designed to go in.  Thus, they could not be assembled and used.
I removed the embossed letters and now the bows fit in the designed slots and can be assembled.
Solar filter material can be purchased from Thousand Oaks Optical.
[https://thousandoaksoptical.com/shop/solar-filters/silver-black-polymer-sheets/](https://thousandoaksoptical.com/shop/solar-filters/silver-black-polymer-sheets/)

I created a filter cutout template using the Boolean modification tool in Blender.
Use an X-acto knife to cut around it.  Getting it trimmed was difficult.  The bottom needed to be really flat and I had to remove more from the sides and nose area to get the filter material to seat down to the bottom.