Ophthalmoscopy is used to understand the structure of the eye and to look inside the fundus of one eye and other structures using an ophthalmoscope. Commonly used to examine retinal and vitreous humor.
Direct ophthalmoscope is the easiest instrument of choice by physicians for fundus examination. This allows a magnified, monocular image of the retina and optic disc.
In direct ophthalmoscopy if the eye is emmetropic, light rays emanating from a point in the fundus emerge as parallel beams.
It is called indirect ophthalmoscopy because, BIO is one of the methods used to view the retina, which has a wide field of view and stereoscopic view of the retina.
The procedure is “indirect” because the fundus is viewed through a hand-held condensing lens.