411 REFERENCE · Wiktionary
Coddington magnifier
Reference material by Wiktionary contributors. This retains its source identity and is not 411 news reporting.
English
Etymology
Popularized and refined by Henry Coddington.
Noun
A magnifying glass consisting of a single thick lens with a central deep groove diaphragm at the equator, limiting the rays to those close to the axis and minimizing spherical aberration.
en Coddington lens
en eponyms