Why do Raindrops appear hexagonal on camera lenses?

Why do Raindrops appear hexagonal on camera lenses?

It is a manif.estation of an optical phenomenon called bokeh, which is Japanese because of the effect of camera equipment on out-of-focus images. In the case of raindrops, it is the result of the diaphragm blades of the camera creating an opening of polygonal shape. The exact shape varies according to the time and the type of camera.