If you have no choice and you really need to clean the lens,
there is a proper way to do it. Don’t get your microfiber cloth right away and
start wiping. This can do the lens a lot of damage.

The best way would be to use air in cleaning it. If you
don’t have a gentle enough and appropriate tool, you can use your mouth.
However, you should never blow on it since your saliva might get to the lens.
The best way would be to cover the end of the lens with your fingers and start
to suck air in from one side. This will eventually suck the dust on the lens if
you do it the right way.