1/32 goggles

Just remember to paint the color of whatever is behind the lenses first, then apply your chosen "glass" medium.

Note, if you use a PVA (aka "white") glue, you need to add a drop of dishwasing soap to get the glue to level.  Used "full strength" it will climb the edges of the frame, and be thin in the middle.

I've often used Testors clear parts cement and window maker to fill inn goggles on figures.

Either gloss clear lacquer (which can be tinted w/clear green if desired), clear epoxy, PVA glue (Elmer's school glue), Future, or any other clear overcoat product can be used.  You may have to use more than one coat to give some depth to the "glass".