eyepiece

views updated

eyepiece (ocular) An eye lens, a fixed diaphragm with cross-wires, and a field lens, all contained in a short tube which is inserted into the top of a microscope. The internal construction of the eyepiece may vary depending on whether the focal plane lies above (Huygenian or negative eyepiece) or below (Ramsden or positive eyepiece) the field lens. Most eyepieces are either 5× or 10× magnification.

More From encyclopedia.com