One of the things that happens to all modern headlights as the car gets old as the sun cooks them, go tea coloured, I have tried a few suggestions from YouTube, with not much luck.
Then, I found an old tin of cheap car wax I forgot about. So I went over a headlight with it, to find the application rag had gone a coffee colour, and to my amazement the headlight came up like new after a bit of elbow grease. It's called Karshine Car Cream.
Well worth a try, can buy it near anywhere for peanuts......Give it a go........😊