The purpose of this study is to estimate the impact of ocular parameters on tonometrically measured intraocular pressure using statistical analysis. Two different tonometers (the Maklakov applanational and pneumatonometer) are discussed. Intraocular pressure readings obtained by pneumatonometer are significantly correlated with central corneal thickness. Maklakov tonometer readings are more affected by corneal curvature and the length of the anterior-posterior axis of the eye then by central corneal thickness, whilst pneumatonometer measurements are not correlated with corneal curvature and the anterior-posterior axis length.