There are two lenses on the compound microscope, the ocular lens and the objective lens. The ocular lens is the lens a person looks into. The objective lens is the lens closest to the specimen.
The two lens system that exists in the compound microscope is designed to increase magnification. The ocular and objective lenses differ in terms of the power of magnification. The ocular, or eyepiece lens, usually gives a power of 10X or 15X. The objective lens has several powers that are normally 4X, 10X, 40X and 100X. The compound microscope is also referred to as a light or optical microscope.