This is a device to measure inner eye pressure. The device is placed, with a weight, on the cornea to measure intraocular pressure. The tonometer was invented Hjalmar August Schioetz (1850-1927) who was the first Norwegian professor of ophthalmology. He developed this device in 1905. The Schiotz tonometer comes with 4 weights, a zero test block, an instruction leaflet and its original fitted box.