Ran down to the dealer yesterday to have my headlights replaced. Although only the right lens had cracked, dealer replaced the entire headlight assembly.
Took 'em less than a 1/2 hour, no worries.
W/O enlarging the images here, it may be tough to see the two cracks that developed. I thought the lens had been struck by a stone but there was no divot or any sign of impact on the surface of the lens, completely smooth.
When I asked about the cause, the dealer wasn't aware of why the lenses were cracking. Lens material defect?
Anyway, new headlights. Good customer support, thank you Triumph!
Ed - 2013 Daytona 675R