Most of all lights have an open vented design to get rid of moisture, even headlights. For decades..
The problem occurs and gets now even worse because of the use of LED lights which are much colder than the old fashioned bulbs.
In the past the heat of the bulbs kept the moist away or dryed the lights quickly. This has changed and is a prob now.
Another issue are colder headlights with HID or even more with LED´s in winter. This is where "premium" car makers have extra heated headlights.
To prevent moisture and blind headlights full of snow that doesn't melt anymore while driving.
The problem occurs and gets now even worse because of the use of LED lights which are much colder than the old fashioned bulbs.
In the past the heat of the bulbs kept the moist away or dryed the lights quickly. This has changed and is a prob now.
Another issue are colder headlights with HID or even more with LED´s in winter. This is where "premium" car makers have extra heated headlights.
To prevent moisture and blind headlights full of snow that doesn't melt anymore while driving.