gonioscope

noun

go·​ni·​o·​scope -ˌskōp 

: an instrument consisting of a contact lens to be fitted over the cornea and an optical system with which the interior of the eye can be viewed

gonioscopic

ˌgō-nē-ə-ˈskäp-ik 

adjective

gonioscopy

ˌgō-nē-ˈäs-kə-pē 

noun

plural gonioscopies