Ophthalmoscope

{offthai’ ’ - mo - shop) [b<p- OaXuog, eye; oicoTceiv, to see]. An instrument for examining the interior of the eye. It consists e entially of a mirror with a hole in it, through which the observer looks, the concavity of the eye being illuminated by light reflected from the mirror into the eye and seen by means of the rays reflected from the eye-ground back through the hole in the mirror. The ophthalmoscope is fitted with lenses of different powers that may be revolved in front of the observing eye, and these neutralize the ametropia of either the patient’s or the observer’s eye, thus rendering the details of the fundus oculi clear. 464