field lens

noun

, Optics.

1. the lens in an eyepiece that is farthest from the eye and that deviates rays toward the center of the eye lens.

Word History and Origins

Origin of field lens¹

First recorded in 1830–40

Example Sentences

I could replace my dead phone, buy a tablet, and finally get that new astronomical refractor telescope, the one with the large field lens and high magnification, all at the top of my “What I Want More Than Anything Else” list—after saving Fig, of course.

From Literature

With such an eyepiece the image viewed is beyond the farther or field lens instead of between the two lenses, and as this fact renders it easier to adjust wires or lines for measuring purposes in the focus of the eyepiece, the Ramsden construction is used when a micrometer is to be employed.

From Project Gutenberg