I was looking for a good product to restore the clarity to my headlight
lenses, and the Sylvania 3-step kit said, "This UV Block Clear coat is a
specially formulated polymer coating with active and passive UV
blockers"

I understand passive UV blockers, but what are active. Do they run up
to the sun and keep it from sending out UV?

I can't copy the url because it's on the other computer.

Anyone happy with what they used for headlight lenses?