Lens manufacturers say that anything other than a microfiber cloth will damage the coatings on a lens. But microfiber cloths eventually pick up crap and they look like they're a pain to wash.
How do you keep your lenses clean? Are you using cloth/kleenex or microfiber cloths? If you use microfiber cloths, how do you clean those?
Same I don't have to wear glasses anymore, but it's was t-shirt all the way. And the occasional "I'll pour water on the lenses to make them more clean".