Haab ophthalmoscope 1889
Haab‘s ophthalmoscope has a disc with 14 lenses. There are six positive and eight negative as well as an empty opening.
These lens are plus 1,2,3,4,6 and 8 diopters and minus 1,2,3,4,5,6,8 and 10 diopters. Haab wanted his condensing lens to not be too small and to have a handle. He settled on a lens of 18 diopters with a diameter of 36 mm. He used the Loring style of tilt mirror.
Manufacturer : R. Dörffel in Berlin, who offered the instrument for sale at a price of 25 marks (about $16 USD in 2015).
