👉 Underglow, also known as "under-illumination," is a term used in medicine and imaging to describe the presence of light or illumination beneath an object or surface. It refers to the process by which light or other electromagnetic radiation can be detected at a lower intensity than visible light, allowing it to penetrate through materials that are not typically transparent. In medical settings, underglow may refer to the level of light or illumination present on a particular part of a body (such as an area
