Intraocular pressure (IOP) is the force exerted by the aqueous humor on the internal surface area of the anterior eye. IOP value is regulated by production and drainage of aqueous humor continuously secreted from the ciliary epithelium of ciliary processes. Disruption of aqueous outflow results in elevation of IOP, the main risk factor for developing glaucoma, which is the second commonest cause of blindness globally, due to the retinal ganglion cell death. Consequently, IOP measurement and reduction are important in detection and treatment of glaucoma. Goldmann applanation tonometry (GAT) is the standard measurement method, but it is affected by corneal properties, such as central corneal thickness (CCT) and corneal curvature (CC), also changed by refractive surgery.