An objective lens of a microscope is responsible for gathering and focusing light from the specimen being observed to produce an image. It is typically located near the bottom of the microscope’s body and consists of a series of lenses that work together to magnify the image of the specimen. The objective lens is called such because it is the lens closest to the object being observed. The magnification power of a microscope is determined by the magnification of the objective lens and the magnification of the eyepiece or tube lens. There are typically several objective lenses on a microscope, each with a different magnification power. The user can switch between the lenses to observe different parts of the specimen at different levels of magnification.