Straps: The goggles are integrated with slots made for 25 mm / 1 inch wide elastic strap. Use a buckle and an adjuster in combination with the strap to assemble the goggles.
Lens: I recommed using a laser cutter to cut 3 to 5 millimeter thick acrylic sheet, and glue the lenses into the recesses of the googles with glue. Please reference the table below for the lens diameter.