At some point during the history of the influencer, the ring light became an accessory de rigueur, fueled by the availability of cheap Chinese-made devices. The original ring light was invented for dentistry by Lester A. Dine in 1952 because of its ability to cast an even light with diffuse shadows in a confined space. An ideal solution for photographing teeth and gums.
The same concept can be found in make-up mirrors, which surround a magnifying mirror with a ring of light. This combination provides a pleasing contrast to overhead lighting that tends to exaggerate lines, wrinkles, and sunken eyes. The advantage of a circular design is that the subject is equidistant from the light source, providing even illumination.