Cap and Weld(not really ... Bridge) work just not how you might think they should.
Delete the end "cap" on the ear-piece tube (I know, it's not technically a tube it's solid alloy ..). Then in the same manner, after applying epoly to the lens frame and entering into face sub selection, delete the closest four quads; you leave another void in the frame oval structure like the one you just created at the end of the ear-piece.
Next, sub-select border (kidney-shaped icon under "Selection" of Editable Poly, after you've added this modifier to the stack of that piece. Making sure you've attached all the glass pieces so they're one entity and are able to see only one object in the scene explorer other than your head, Ctrl+ select both an ear-piece and a frame-hole.
Now, choose Bridge Settings (right beside the "Bridge" button) from "Edit Borders" in EPoly modifier, choose the settings you want to define the detail of the "weld"(sp). And the previously separate entities should now be entirely connected.
You could also NOT use Bridge and use Weld instead. But you've got to get rid of those caps either way.