the lens in an eyepiece that is farthest from the eye and that deviates rays toward the center of the eye lens.
Retro Words You’ll Probably Never Use AgainMost of these retronyms -- obsolete words and phrases -- are outdated technologies.
Origin of field lens
First recorded in 1830–40
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for field lens
The object looked at requires to be a short distance in front of the field-lens.The New Gresham Encyclopedia|Various