'Wollaston's doublet' definitions:

Definition of 'Wollaston's doublet'

From: GCIDE

Wollaston's doublet \Wol"las*ton's dou"blet\ [After W. H. Wollaston, English physicist.] (Optics) A magnifying glass consisting of two plano-convex lenses. It is designed to correct spherical aberration and chromatic dispersion.
Note: Under "wollastonite" the eponymous inventor is described as a chemist. [Webster 1913 Suppl. +PJC]