Lightning damage could only be reduced, but can not be guaranteed like "keep away from my device".
To fiber optic transmission systems, they usually add independent anti-lightning chips on PCB port, and make sure grounding, so that can reduce the rate of damaging by lightning.
BTW, F.O. products designed with surge protection, to provide device working safely in any different current level.
So far as i knw, there are only a few Chinese company's F.O. products designed like that, and indeed, their products do good performance in outdoor.
