Many environmental factors including UV radiation, salt air and road grime over time can slowly breakdown the protective coating applied to your polycarbonate headlight lenses.
In many states of Australia and especially Victoria it is illegal and your vehicle is considered unroadworthy if your headlights are discolored. You could be fined or a defect notice issued.
Knights Glass offers a 12-month warrantee as we include a UV ceramic coating on all headlight restoration.
We can restore headlights that are bad. We are happy to do a free online assessment should you be unsure.