Originally posted by csa Just my own feeling; but I don't use lens pens on any of my glass. If a tiny particle of dirt gets caught on the lens pen, then that particle gets scratched across the surface you are cleaning. I've simply used a blower, and a light touch of a soft brush.
Unless that tiny particle is made of a very hard material, it's not gonna do any damage to your lens. And you can brush it off anyway, then use a cloth or whatever to remove the smudges (which do find their way on lenses and cannot be removed with just some air or a brush).
People need to stop treating specially hardened and coated glass that was designed to be exposed to the world like porcelain ...