Here's why:
* Bright illumination: Compound light microscopes use a light source to illuminate the specimen. This light is usually directed through the specimen and then through the lenses, producing a bright image.
* Multiple glass lenses: They have multiple lenses to magnify the image. The objective lens, closest to the specimen, provides the initial magnification, and the ocular lens, closest to the eye, further magnifies the image.
While other types of microscopes exist (like electron microscopes), the compound light microscope is the most common type that uses bright illumination and multiple glass lenses.