In cold or damp weather, the inside of the lamp lenses can mist up because of the temperature difference between inside and outside. This is normal and does not shorten the life of the lights.
Once the lights have been on for a while, the mist clears gradually. With the low and main beams on, misting in the headlights usually starts to clear within 30 minutes, though some may remain at the edges for a while.
Warning:Follow the guidance on driving through water (depth, speed) so water does not get into the lights. If you remove a lamp dust cover, refit it properly afterwards.
Warning:When replacing a bulb, make sure all lamp parts are fitted and sealed correctly. Check the rear cover's seal ring is in place and clean, or water and dust can get in.
Warning:Never use a pressure washer on the engine bay, and especially not on the lights. The high pressure can loosen parts and let water into vents and connectors, causing long-lasting condensation.