Under normal circumstances, many people are not very clear how to distinguish whether the headlights are flooded or foggy. They often think that they are flooded when they see water droplets. In fact, there is a preliminary way to judge whether the headlights are flooded or foggy, which is to check the traces of the water flow.
We know that when the headlight enters water, it usually enters the water from above the headlight and then flows under the headlight. This will form obvious water traces. Similar to a waterfall, even if the water is dry, there will be some traces. As the road that a snail passes will have traces, an experienced master can see it.