Medical Antiques > Medical Diagnostic Instruments

Berens-Tolman Ocular Hypertension Indicator

Item#: MED1246



Berens-Tolman Ocular Hypertension Indicator - click to enlarge.

The Berens-Tolman Ocular Hypertension Indicator was invented in 1950 by Conrad Berens and Charles P. Tolman. It is a screening instrument to indicate whether the intraocular pressure is below or above normal and it is not a diagnostic instrument. The indicator uses the footplate and plunger like those of the Schiötz tonometer. The weights of these parts correspond to the Schiötz tonometer. 20 mm hg, The reading however is an indication and not an absolute number. The instrument is about 6.5 cm long and inscribed – Berens Tolman Ocular Hypertension Indicator CP Tolman US Pat 2.656.715 RO Gulden Phila Ma Mid Line + 20mm Hg. The indicator comes in its original box. R. O. Gulden Company was founded in 1938 as a manufacturer of ophthalmic instruments and devices in Philadelphia Mass USA.