Purpose: Several characteristic personality types have been reported for glaucoma patients in previous studies. However, none of the previous studies used a common structural theory of personality. In this study, we conducted a multicenter cross-sectional case-control study using the recently established five-factor model of personality structure. Methods: Personality was evaluated using the Neuroticism Extraversion Openness Five-Factor Inventory (NEO-FFI), which is a questionnaire specifically designed to test the five-factor model of personality: neuroticism (N), extraversion (E), openness (O), agreeableness (A), and conscientiousness (C). Eligible questionnaires were obtained from 196 patients with primary open-angle glaucoma (POAG) (99 men, 97 women) and 223 reference subjects with no ocular disease except cataract (87 men, 136 women). The mean score of each NEO-FFI factor for POAG patients was compared to the scores for the reference subjects. Results: Compared with the reference subjects, the mean N score was significantly higher (P=0.013), the mean scores for A and C were significantly lower (P=0.007 and P=0.001, respectively), and the mean E score tended to be lower (P=0.055) in male POAG patients. The mean E score was significantly lower (P=0.023) in female POAG patients. Conclusions: Characteristic personality traits were noted in POAG patients, and a more significant relationship was found between personality and glaucoma in men than in women. Purpose, Several characteristic personality types have been reported for glaucoma patients in previous studies. However, none of the previous studies used a common structural theory of personality. In this study, we conducted a multicenter cross-sectional case-control study using the recently established Methods: Personality was evaluated using the Neuroticism Extraversion Openness Five-Factor Inventory (NEO-FFI), which is a questionnaire specifically designed to test the five-factor model of personality: neuroticism (N), extraversion (E), openness (O), agreeableness (A), and conscientiousness (C). Eligible questionnaires were obtained from 196 patients with primary open-angle glaucoma (POAG) (99 men, 97 women) and 223 reference subjects with no ocular Disease except cataract (87 men, 136 women). The mean score of each NEO-FFI factor for POAG patients was compared to the scores for the reference subjects. Results: Compared with the reference the mean scores for A and C were significantly lower (P = 0.007 and P = 0.001, respectively), and the mean E score tended to be lower (P = 0.055) ) in male POAG patients. The mean E score was significantly lower (P = 0.023) in female POAG patients. Conclusions: Characteristic personality traits were noted in POAG patients, and a more significant relationship was found between personality and glaucoma in men than in women .