The aim of the study was to determine adherence rates and beliefs about glaucoma and its treatment in white Americans, African Americans, white Australians and Singaporeans of Chinese descent. A cross-sectional study of 475 glaucoma patients using topical eye drops for at least six months was carried out. Adherence was assessed using an adaptation of the self-report measure the Reported Adherence to Medication validated questionnaire. The authors found significant differences in the age, duration of treatment for glaucoma and level of education between the groups. Overall they found that self-reported rates were fairly high for all groups. For example, Singaporeans reported significantly lower understanding of their glaucoma than any other group and also believed less strongly in the ability of their eye drops to control glaucoma compared with all the other groups. African Americans were significantly more concerned about their glaucoma than any other group and also reported to be more effected emotionally by glaucoma. Australians experienced significantly more symptoms from glaucoma and believed that glaucoma had a greater impact on their life. This study revealed significant differences in self-reported adherence between glaucoma patients from diverse cultures.