Source : Webster's Revised Unabridged Dictionary (1913)

Ophthalmoscope \Oph*thal"mo*scope\, n. [From Gr. ? the eye +
   -scope.] (Physiol.)
   An instrument for viewing the interior of the eye,
   particularly the retina. Light is thrown into the eye by a
   mirror (usually concave) and the interior is then examined
   with or without the aid of a lens. -- {Oph*thal`mo*scop"ic},
   a.

Source : WordNet®

ophthalmoscope
     n : medical instrument for examining the retina of the eye