Huygenian eyepiece
noun
Huy·ge·ni·an eyepiece
| \ ˌhī-ˈgē-nē-ən-
, ˌhȯi-
, -ˈgen-ē-\
, ˌhȯi-
, -ˈgen-ē-\
variants:
also Huygens eyepiece \ ˈhī-gənz-
, ˈhȯi-
\
, ˈhȯi-
\
Medical Definition of Huygenian eyepiece
: a compound eyepiece used especially with achromatic objectives that consists of two plano-convex lenses separated by a diaphragm with the convex sides facing the objective