Yellowed, hazy headlights cut night-time vision by up to 70%. The cause: UV degradation of the plastic lens. A new headlight assembly is $300–$800 per side.
A $20 headlight restoration kit (Sylvania, 3M) sands, polishes, and re-coats the lens in an hour of DIY work. Results last 2–3 years.
If you can't see at night because of haze, you're a hazard. Fix this weekend.
