thanks, and think I can see the alternating pattern on the left hand piece, but the background in this picture Michael is too busy and with different colours/shades for an easy id on the screen only, although appreciate that for you there isn't a problem.
Details on clear glass can be difficult to see at times, and a plain darkish background with some form of light to pick up patterns, will make all the difference. Perhaps if you lay the glasses down, on the dark sheet, it might improve the contrast.