For decades, the gold standard for intraocular pressure measurement has been the Goldmann applanation tonometer. The Goldmann tonometer is calibrated based on a central corneal thickness of 500 micrometers. But, it is known that CCT varies between individuals and even between individual eyes. The various central corneal thicknesses (CCT)s are thought to influence the accuracy of IOP measurements and thus the diagnosis, screening, and treatment of patients with glaucoma. A study performed by Copt (1999) showed that ocular hypertensive patients have relatively thick corneas and normal tension glaucoma patients have relatively thin corneas. Thus it is thought that a thicker cornea creates falsely high IOP readings and a thinner cornea creates falsely low IOP readings. This was followed by a study performed by Lleo et al (2003) which showed that applanation tonometry and CCT positively correlated in normal eyes. More recently the following studies have also found a positive correlation between CCT and tonometry: Lui et al (2005), Tonnu et all (2005), Pourjavan et al (2005), Doyle et al (2005), Gunvant et al (2005), Brunsini et al (2005) and Rask et al (2005).