I want to get some glasses/eye shields to keep the wind, dust and bugs out of my eyes. I'm not in the market for the stupidly priced items but a couple have caught my eye (no pun intended!). These are the Madison D'Arcs and Bloc something or other from Evans' website. For those that don't know, both come as a set with three different coloured lenses. Question is, do folk ever actually bother changes the lenses from clear to citrus to smoke or do you just stick with one indefinitely? Any words of wisdom from existing users particularly welcome.