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The streets are full of people driving cars with headlights that do not work.
When it was decided in the early Eighties, that cars needed to be "streamlined", manufacturers started making headlights with their own reflectors and clear plastic front covers, to replace the uniform self-contained glass "sealed beam" headlights used since 1940. The problem is that sunlight and sundry environmental effects eat into the surface of the clear plastic windows and eventually turn them from transparent to translucent -- which is to say, no longer clear.
If you didn't ever realize that translucent windows don't throw light forward, which is what headlights are supposed to do, you might be driving around with headlights that don't light anything, at least not anything in front of you. They glow but they don't throw.
Recently (only about 25 years from the onset of plastic headlight windows), window resurfacing kits have started to appear in the auto parts stores. But still, most people have never heard of them; most people don't realize that this is a problem that they have and that they can fix.
Presuming that you want to see where you're going at night, you need to polish the decayed material off the headlight windows. It can usually be done with a condemned t-shirt and some inexpensive standard polishing compound* (which is a fine abrasive) from the auto store, and some good hard, committed rubbing.
You can use the expensive commercial headlight-specific kits it you want, but don't use anything with silicone polish in it. Over time, silicone will make the problem worse.
And by the way, could we please have a law requiring that every state vehicle inspection comes with a headlight-polishing if it's necessary? Otherwise, many people are driving without functioning lights, and part of the inspection is to make sure that people are driving around with functioning lights.