The ophthalmoscope is an instrument that allows observation of the eye, the retina and retinal vessels. Its use allows the diagnosis of many diseases and is relevant to ophthalmology and general medicine for treatment of diabetes and arterial o hypertension. The procedure is conducted in a dark environment. The pupil is dilated with the insertion of appropriate medicine (atropine) in the conjunctival sac.
First ophthalmoscope was invented by Charles Babbage in 1847, but was unsuccessful. The ophthalmoscope accepted by ophthalmologists was that created by Hermnann van Helmotz in 1851. It comprised of an indirect ophthalmoscopic light consisting of a convex lens placed between observer and patient, which provided a real, inverted and an image enlarged three times, in 1915, Allin and Welch introduced the direct ophthalmoscopic light, which enabled obtaining of two virtual images: proportional and magnified 15 times. The ophthalmoscope in use today by the oculists is a refinement of the later version.