Aim: To compare rarebit perimetry (RBP) with standard achromatic perimetry (SAP) in detecting early glaucomatous functional damage. Methods: 43 patients with ocular hypertension (OH),39 with early primary open angle glaucoma (POAG), and 41 controls were considered. Visual fields were assessed using the Humphrey field analyser (HFA)30- 2 and RBP tests. Differences among the groups were evaluated using Student-Newman-Keuls and χ 2 tests. Correlation between HFA and RBP parameters was assessed using the Pearson’ s correlation coefficients and regression analysis. Sensitivity and specificity of RBP in detecting early glaucomatous visual damage were calculated with different algorithms. Results: RBP-mean hit rate (MHR) was respectively 88.6% (SD 4.8% ) in controls; 79.1% (10.9% ) in the OH group; 64.3% (13.8% ) in the POAG group (differences statistically significant). Good correlation in the POAG group was found between HFA-mean deviation and RBP-MHR. Largest AROC (0.95) and optimal sensitivity (97.4% ) were obtained when an abnormal RBP test was defined as having (at least 1): MHR 15 areas with a non-hit rate of >10% ; ≥ 2 areas with a non-hit rate of >50% ; at least one area with a non-hit rate of ≥ 70% . Conclusions: The RBP appeared to be a rapid, comfortable, and easily available perimetric test (requiring only a PC device), showing a high sensitivity and specificity in detecting early glaucomatous visual field defects. Methods: 43 patients with ocular hypertension (OH), 39 with early primary open angle glaucoma (POAG), and 41 controls were considered Visual fields were assessed using the Humphrey field analyzer (HFA) 30-2 and RBP tests. Differences among the groups were evaluated using Student-Newman-Keuls and χ 2 tests. Correlation between HFA and RBP parameters was assessed using the Pearson’s Results of RBP-mean hit rate (MHR) were 88.6% (SD 4.8%) in controls; 79.1% (10.9% ) in the OH group; 64.3% (13.8%) in the POAG group. Good correlation in the POAG group was found between HFA-mean deviation and RBP-MHR. Largest AROC (0.95) and optimal sensi RBP test was defined as having at least 1: MHR 15 areas with a non-hit rate of> 10%; ≥ 2 areas with a non-hit rate of> 50%; tivity (97.4%) were obtained when an abnormal RBP test was defined as having At least one area with a non-hit rate of ≥ 70%. Conclusions: The RBP was to be a rapid, comfortable, and easily available perimetric test (requiring only a PC device), showing a high sensitivity and specificity in detecting early glaucomatous visual field defects.