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?
I guess? I space 10 years between photoreactive lenses, and although I've only done it twice, I didn't see any improvement between in the intervening years.
I haven't tried the most modern version, but they've never darkened enough, and they don't lighten quickly enough. On top of that, the shelf life of the photoreactivity is crap, and the performance degrades quickly, forcing me to replace my lenses more frequently than I otherwise would. IME, photoreactive lenses are just a contract to buy new glasses in few years.