Headlight Condensation

My front driver side headlight has been having major condensation issues, it's definitely not water leaking in, as it's only happening during colder weather. I disassembled the headlight, and had applied silicone glue around the seams and had did my own water test by filling up the headlight and then blowing on one of the holes (to see if their was a leak where water was entering) but there was nothing. I thought maybe the silicone glue should do the trick. Fast forward now, the issue still exists, I've also noticed ever since I cleaned the headlight, the light coming from the headlight doesn't seem too strong, maybe when I tried cleaning the lamp I did a poor job, so I'll have to go back and double check on that.

So I'd like to ask, what other culprits can be causing this condensation? I know I can go out and get a new headlight, but I'm trying to hold off on that for now, especially since I rarely drive at night, it's just hideous to look at with all the water inside. Attached some pictures of what the headlight looks like as of right now.

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Lol, yes I did dry the headlight completely when I sealed it, I used a heat gun (I made sure to set it up so it doesn't melt the headlight, just keeps the box which I stored it in warm to dry the condensation).

There was no condensation couple of days ago, as it was a bit warm. The weather has gotten colder, and that's when I saw the condensation.

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I understand that, but I do want to note, I cleaned the few weeks go, where the weather was around low to high 50 degrees Fahrenheit. I had made sure that no form of condensation left, I did this leaving ta heat gun on for roughly 30 minutes in a cardboard box, and keeping a thick cardboard in between the headlight and heat gun (so it doesn't damage anything), then used compressed air for 10 minutes and there was literally nothing. This was all done when the headlight was disassembled.

Which is why I ask what other things could be the cause, I've seen a lot of Gen 3 Prius's with this problem, but when I disassembled the headlight, I saw no possible areas for water to get in, and tiny cracks or holes.

Well, as I mentioned, I had resealed the entire headlight with quality silicone glue. I even went further by pouring water into the headlight, then blowing through one of the headlights holes (while covering the others so it doesn't blow out from there) to see if there was a possible hole/leak, but nothing. For reference, I did pretty much exactly what this video does:

EDIT: Typos and a merge

 

It has been driven during the rain and snow, but the water never was going inside the headlights (as I also washed the car quite few times, and nothing happened then either). I always park the car outside, but the water really started to buildup once the weather got cooler

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I did not, I tried pretty much everything, from literally cleaning the glass where the bulb projects with soap, to something a bit more abrasive. I, however, did manage to fix the condensation problem, by doing a good ol' New Yorker 'hood mechanic style: drill couple of holes on the headlight. The holes being drilled instantly cleared up all water condensation. I have to assume that the long periods of condensation just damaged the projecting glass thingy which made the light seem dim. I instead just bought a new headlight assembly.

You can go through all the things, but I eventually realized, for something as a headlight, I'd rather just fix it as soon as possible then delve on with creative ideas to solve the problem. If water getting inside/condensation is the problem, and not dim lights, and the seals around the headlight seem fine, I'd personally just drill a hole (or two), might be frowned upon here, but I'd do it an the area that is facing down towards the ground, and if you do it right, it shouldn't even be visible unless you get close enough, or point out the holes.

 

Honestly, that is my suspicion. I bought new headlights and the passenger side sometimes has some water inside and it really ticks me off because I spent quite a bit on them. I noticed at times the seal where the bulbs go into the headlight to have some water, so that may likely be the fault to the condensation issue. Fortunately, I noticed that once I start driving ~10 minutes, the water usually goes away, so I assume if it isn't developing in large amounts, it isn't terrible. Nonetheless, it definitely is an issue for the 2010-2011 Prius's as I have seen quite a few Prius's of those years with similar headlight issues.