Damp salt covered roads can cause a problem keeping your visor clean.
Take a washing machine soap dispencer cut two small holes in the side for a cable tie add a bit of wet sponge and attach to the handle bar or mirror stalk.
My trick is to use a J cloth attached to a belt key holder, the spring return type. the holder is then cabled tied to the bars. It is easy to wipe your visor and when you let go it springs back.
Take a washing machine soap dispencer cut two small holes in the side for a cable tie add a bit of wet sponge and attach to the handle bar or mirror stalk.