| Share
 

ophthalmoscope

ophthalmoscope (ŏfthălˈməskōpˌ) [key], instrument used for examining the inner structure of the eye. The device was invented by the German physiologist H. L. F. von Helmholtz in 1851. His model consisted of three plates of glass pressed together and mounted on a handle at a 45° angle. A light was placed beside the subject whose eyes were to be examined. Some light passed through the plates, but some was reflected back into the eye. The form of the instrument now in general use consists of a concave mirror and a battery-powered light source within a tubular handle. Sighting is through a single or binocular eyepiece. The ophthalmoscope is equipped with a rotating disc of lenses to permit observation of the eye at varying depths and magnifications. Examination of the eye may be enhanced by administering drugs to dilate the pupil.

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.

More on ophthalmoscope from Infoplease:

See more Encyclopedia articles on: Medicine


Premium Partner Content
HighBeam Research
Documents Images and Maps Reference
(from Newspapers, Magazines, Journals, Newswires, Transcripts and Books)

Research our extensive archive of more than 80 million articles from 6,500 publications.

Additional search results provided by HighBeam Research, LLC. © Copyright 2005. All rights reserved.

24 X 7

Private Tutor

Click Here for Details
24 x 7 Tutor Availability
Unlimited Online Tutoring
1-on-1 Tutoring