What is "orthoscope"

Orthoscope \Or"tho*scope\, n. [Ortho- + -scope.] (Physiol.) An instrument designed to show the condition of the superficial portions of the eye.

n. 1 An instrument for examining the interior of an eye. 2 An instrument for drawing projections of a skull.

n. an ophthalmoscope with a layer of water to neutralize the refraction of the cornea