If condensation is getting into your headlights, and there are no visible cracks or damage, there’s likely a problem with a seal, gasket or a drainage hole. In some states, waterlogged headlights won’t pass inspection. Even if you take the lenses off and dry them, the problem is likely to reoccur unless you replace all of the components.
If you’ve got a lot of water built up in your headlights, the easiest way to clear it out and keep them clear is to drill a very small hole at the bottom-most part of the headlight so water can drain.
Consult your vehicle owner’s manual to determine how to access the headlight assembly. Follow the instructions to gain access. This is usually accomplished by opening the hood and removing the back of the assembly or unscrewing the bulb.