This document discusses intraocular pressure (IOP) measurement and different types of tonometry. It defines IOP and tonometry, and lists the normal IOP range. It describes the goldmann applanation tonometer as the gold standard method, which uses the Imbert-Fick principle to measure pressure based on the force needed to flatten a given area of the cornea. It also discusses schiotz indentation tonometry, rebound tonometry, and digital tonometry as alternative methods. The document provides details on using and disinfecting each type of tonometer, and lists some contraindications.