Final answer:
A microscope with one eyepiece is known as a monocular microscope. Monocular microscopes are one of several types, which also include binocular and trinocular microscopes.
Step-by-step explanation:
The name given to a microscope with one eyepiece is monocular. This is distinct from binocular microscopes which have two eyepieces, and trinocular microscopes that have a third eyepiece often used for a camera attachment. Compound microscopes typically use an arrangement of two convex lenses to increase the magnification of the sample; these include the ocular lens or eyepiece closest to the eye, and the objective lens closest to the sample. The overall magnification of a compound microscope is calculated by multiplying the magnification of the objective by the magnification of the eyepiece.
If a microscope has an overall magnification of 800 and an objective that magnifies by 200, then the eyepiece magnification can be found by dividing the overall magnification by the objective magnification. So, the eyepiece magnification would be 800/200 = 4. Additionally, if other objectives with magnifications of 100 and 400 are available, the possible overall magnifications with the same eyepiece would be 100 x 4 = 400 and 400 x 4 = 1600, respectively.