Giantscope ophthalmoscope
 Catalogue Number: 2011 Giantscope ophthalmoscope Category: Equipment Sub-Category: Ophthalmoscope Year Of Publication/Manufacture: c1936 Time Period: 1900 to 1939 Place Of Publication/Manufacture: USA Publisher/Manufacturer: American Optical Company Description Of Item: Black metal & glass ophthalmoscope with internal illumination and connection for power supply lead. Engraved:'No 144P GIANTSCOPE/ AMERICAN OPTICAL CO/ U.S.A.' Rear marked:'US PATENT No/ 1,918,848/ 1,951,664/ 1,956,867/ 2,078,254/ PAT. PEND./ MADE IN/ U.S.A.' Three coloured filters to rear of instrument; green, blue, amber. Wheel of lenses +7 to -8 in 1D steps. Supplementary lenses:+16. +8, plano, -16, -22 D. The instrument features a polarizing filter to lessen corneal reflections, to which the patent numbers refer. It has a black leatherette covered case with burgundy velvet lining, hinged lid and 2 slide button catches .Case Dimensions: L:24.5cm x D:11.3cm x H:5.0cm. Instrument: 225 x 42 x 25 mm. Historical Significance: The Giantscope was first produced in 1926. It was one of the first ophthalmoscopes to use a polarizing filter to lessen corneal reflections. The first three patents were granted in 1933 & 1934. The fourth was not granted until April 27, 1937. All were for Edwin H Land's inventions for polarizing filters. How Acquired: Not known Condition: Very good Location: Archive Office. Cabinet One Drawer 12 |