Most headlight lenses are made of polycarbonate, a plastic that is vulnerable to UV radiation from the sun, causing them to become yellowed or cloudy over time. Lenses are also prone to scratches and gouges.

While it requires some time and effort, headlight lenses can be restored to near-factory condition through sanding and polishing. In this video, Polyvance demonstrates the process of restoring a deeply scratched headlight to like-new quality.