what is the function of the eyepiece on a microscope

The eyepiece, also known as the ocular lens, is the lens nearest to the eye on a microscope. Its main function is to magnify the image produced by the microscopes objective lens so that it can be seen by the human eye. The eyepiece and objective lens work together to project the image of the object onto the eye or a sensor, depending on the application. The eyepiece typically produces an additional 10X magnification, but this can vary from 1X to 30X. The total magnification of a microscope is determined by the sum of the magnification of the eyepiece and the objective lens. The eyepiece can also have additional features, such as a movable pointer located within the eyepiece and positioned so that it appears as a silhouette in the image plane, which is useful to indicate certain features of a specimen, especially when a microscopist is teaching students about specific features. Additionally, the microscopist can adjust the telescopic eyepiece so that it is parfocal with the ocular eyepieces to make it easier to frame and take photomicrographs.