1) Ophthalmoscope 
• (n.) An instrument designed to show the condition of the superficial portions of the eye.
(or´tho-skōp) an apparatus that neutralizes corneal refraction by means of a layer of water; used in ocular examinations.
Or'tho·scope noun [ Ortho- + -scope .] (Physyol.) An instrument designed to show the condition of the superficial portions of the eye. 
Type: Term Pronunciation: ōr′thō-skōp Definitions: 1. An instrument by means of which one is able to draw the outlines of the various normas of the skull.
[n] - an ophthalmoscope with a layer of water to neutralize the refraction of the cornea
orthoscope A stereoscope used for evaluation of the relative image size of the two eyes.
noun an ophthalmoscope with a layer of water to neutralize the refraction of the cornea
(formerly) an instrument for examining the internal structures of the eye through a layer of water that neutralizes the refraction of the cornea.