Indirect ophthalmoscopy is a method of fundoscopy which has come into increased prominence during the last decade. In this method, a convex lens is held before the patient's eye and an inverted real image of the fundus is produced in the air between the observer and the lens. This image can then be studied in various ways by the observer.
In 1947, Dr. Schepens devised a selfluminous binocular indirect ophthalmoscope1 which allowed the visual axes, by means of reflecting surfaces within an eyepiece arrangement, to become paraxial with the light source beam. The outstanding feature of this instrument was, and is today, the relatively large fundus field that can be examined stereoscopically and with intense illumination. The magnification of the retinal image with this conventional ophthalmoscope is low, however, and varies as an inverse function of the power of the convex lens used. Any increase in fundus magnification, obtained
L'ESPERANCE FA. Greater Image Magnification in Indirect Ophthalmoscopy. AMA Arch Ophthalmol. 1959;62(6):1096-1098. doi:10.1001/archopht.1959.04220060168012