Bible Dictionaries
Iris Diaphragm

Webster's Dictionary

An adjustable diaphragm, suggesting the iris of the eye in its action, for regulating the aperture of a lens, consisting of a number of thin pieces fastened to a ring. It is used in cameras and microscopes.

Bibliography Information
Webster, Noah. Entry for 'Iris Diaphragm'. Noah Webster's American Dictionary. https://www.studylight.org/​dictionaries/​eng/​web/​i/iris-diaphragm.html. 1828.