After a new Headlamp or a new Bulb is replaced, Water droplets can found on the inside of the headlamp (Usually after a car wash or rainy season) these are often a misconception of a defective headlamp.
These fine water droplets did not come from outside the headlamp but are actually precipitation of the humidity inside the headlamp settling on the cooler surface of the lens after experiencing fluctuation of temperature.
The condensation will clear as you drive with the headlamp engaged and sometimes may take about a week to fully clear.

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