I worked on a system using two fairly powerful lasers to scan eyes (yeah, I know).
Obviously, we worked in a closed off space so others would be safe - the oscillating mirrors could throw light everywhere during development and one had to be careful, which is difficult for hours on end.
The safety mechanism? wearing glasses with a high-Q optical filter for the two frequencies involved, not unlike the film over the aircraft screen idea.
So, no retrofit, give pilots laser landing glasses with maybe two filters for red/green. Going forward, ensure that all manufacturers agree that commercial pointers etc. use almost the same frequencies to minimise the variance.
The glasses were almost perfectly clear I recall so it seems possible unless there are dozens of frequencies used at the moment, even so, maybe a wider filter would still be fine even at night (where I presume the most attacks occur?, after all, they want to see the dot on the aircraft not being actual terrorists a la ISIS?).