I have purchased two pairs off glasses, one double one single, to use whilst rowing my single racing scull on a very busy Noosa river. These glasses are fantastic, I particularly like the lense with the vent at the top ( only comes with the double mirror) this stops clouding the view in our very humid tropical conditions. I can now see over the bow ball and I feel much safer. I would like to try a larger mirror than the one now offered. They may be available in Europe. Also, it may be an idea to mount the mirror higher up the side of the glasses. This would allow a continuous view without moving the user head up and down. I highly recommend this product. Peter McIntosh NYRC Queensland, Australia