It’s the first time it’s appeared in mine after 7 and half years. Probably the temperature extremes over last few months and not getting much use. Put one of lights in a slightly warm oven for a few minutes and it’s mostly gone now.. maybe once condensation is in there it’s difficult to get out unless you take the bulb cover off at the back of the light

Remove the headlamp in question, then put it in the airing cupboard for a couple of days, with all the bulbs are and covers removed. This will give sufficient warmth and dryness to remove the condensation. Make sure you put all the bulbs back in and covers back on before taking it outside again. 2009 Rimini Red SE TD4. Soon to be sold.
Hyundai Ionic 5 Ultimate on order.
Gone. 2006 Tonga Green i6 HSE.

You need to warm up your headlamp as suggested by others but you also need to get the damp air out and dry air in. A hair dryer on warm is a possibility. There should be a Gortex covered vent on the the back of the headlamp somewhere. This is supposed to let air out as it warms and in as it cools without allowing in moisture. It might have become unglued.

I looked at my headlight last time I had it out and couldn't see any vent. When the warmer weather arrives - it comes pretty late up here !- I 'll take it out and have another look. I'll then give it a thorough drying out.

Pretty sure the problem is that once moist air is inside it doesn't escape, and just constantly evaporated and condenses according to the temperature. In winter I am often driving through surface water mostly on the nearside and that's the headlight I have the problem with. FL2 SD4 XS 2013 Orkney Grey

Yes. I think once the condensation gets in, you need to dry it out with the back off. Before I dried mine , the condensation didn’t seem to have any means of escape until I took bulb cover off. No membrane on mine I don’t think. 2014 model

Lakelander wrote:

Dano64 wrote:

It’s appeared in both my headlights now . It comes and goes. Have dried one out indoors so we’ll see

Mine now 99% cleared , but it's been there over 3 months! and this happens each winter.
My theory is that cold water spray gets in when driving through puddles on the nearside .
Then there is not enough heat and too much humidity to dry it out until regular sunshine arrives. The units are not fully sealed and have a big glass area.

I put cilica gel in a cotton pouch into the rear of the light unit no more problems.

Thanks that's a really good idea  FL2 SD4 XS 2013 Orkney Grey