Had to replace my LHS lens after the mirror assembly took a hit from an approaching overtaking vehicle encroaching into 'my' lane (typical mainland China driving etiquette). Attempted to find just the lens unsuccessfully, and ended up buying the whole LHS indicator assembly from oneidasuzuki sent to a friends relatives house in the USA, - my friend bought the item back in his luggage on a recent China-USA-China trip.
I contemplated fabricating a "lens" from some perspex, but since I needed a few additional items, added the LHS indicator (complete with lens) to my order at the time. Swapping the component out from the mirror pod is simple. Remove the little plastic retaining grommet, then unscrew retaining screw underneath then prise the lens and housing forwards out of the mirror pod.