Albrecht von Graefe’s invention of the surgical iridectomy procedure for the treatment of glaucoma in 1857 was his impetus to design an instrument to measure the eye pressure so that he could record pressures before and after iridectomy. He also constructed a campimeter for plotting the visual field. His design for a pressure measuring instrument was developed into the first tonometer in 1863. It was however unsuccessful. This was followed by several attempts and a series of tonometers by …