eyepiece
noun
- type of lens attached to a variety of optical devices such as telescopes and microscopes; usually the lens that is closest to the eye when someone looks through the device, placed near the focal point of the objective to magnify the image
Wiktionary
noun
Etymology: From eye + piece.
- The lens (or the component containing a combination of lenses) at the eye end of a microscope or telescope by which the image is viewed.