Why do your car windows have mysterious black dots

This small but important detail on windows has surely caught your attention, especially since it can be found in almost every modern car. Older models usually do not have these dots. However, it is not a "fashion" in the automotive world, but rather a technical solution worth knowing.

The black dotted border around car windows, known as the frit, enhances driving safety. The dots on rearview mirrors are essential as they help prevent the driver from being blinded by the lights of cars behind. They also divide the image into two visual zones: aspheric and spherical.

The aspheric zone broadens the field of view, eliminating blind spots, which is crucial for safe driving. Nonetheless, many drivers do not appreciate this solution, although it is a kind of "sensor" that is worth utilizing. The spherical zone characteristic of older car models is less technologically advanced.

The frit also serves as a mask for the window's adhesive. It protects it from the harmful effects of ultraviolet rays, extending its life. Of course, one cannot forget the aesthetic aspect. The dots trick our eyes, making the transition between the clear glass and the black borderless abrupt.

Dots are applied to windows during the production process, mainly by screen printing. This method makes the glass durable and resistant to damage. Screen printing also ensures stable mounting, as the adhesive adheres better to the surface with dots, which is extremely important, especially in the context of changing weather conditions. Factors such as heat or cold can affect the durability of the mounting. Still, the presence of black dots helps prevent this by minimizing heating the vehicle's interior in summer.

Finally, the frit on the window can also determine the car's production date—the number of dots indicates the month, and the visible number indicates the year. This allows us to easily determine the originality of the vehicle's windows.