You will have to change them anyhow in the near future.
The plastic clear lens deteriorates with time from the elements and also from the heat/uv generated from the bulbs.
If the cloudiness is from the outside, you can go for restoration.
A DIY approach is also there using toothpaste, which has abrasive particles to clean the outer lens.
Try this in a small part of the headlamp and see if you can clean it. If successful, cover the whole headlamp. This should clean up somewhat and you will see better than how it is now.
After some period of time if it deteriorates, just replace them with new ones.