Hair loss can occur on one side of the scalp that is exposed to more sun than the other side

This happens when a person drives a car or truck for a living, the side on the window gets more sun exposure than the other side causing damage from to the skin and more hair loss. We can see this very well in the photo below, of a truck driver whose face aged more on the drivers side of his face.  For people who drive in Australia, the opposite occurs because they drive on the other side of the road.