I'm using a lens 'pen' designed for cameras - about the size and shape of a marker pen, one end is a brush to get rid of loose dirt or dust, the other is a circular flat/slightly concave disc that is used in a circular motion to 'polish' the lens. This has been brilliant and is easy to carry with me too.
What I'd be interested in is what people use to clean the glass of their bins with - I noticed after a recent stalk that as I'd had to crawl through damp grass, the front lenses now have streaky marks on them, and this is not removed when using the above pen... As Pault says, I don't want to ruin the coatings, so what should I use to get the glass back to its optimum clarity?
Pippa