Matt A wrote a review of Smith Spoiler Replacement Lenses on May 12, 2014
Familiarity: I've put it through the wringer
I've had several pairs of Smith Spoilers and they are the most user friendly design to change out the lenses. These lenses are very durable and are highly scratch resistant. I would highly recommend the Polarized Gray Green for bright days as they cut glare exceptionally well and the Ignitors for flat light days when driving or mountain biking.