Background: Until advanced, glaucoma is asymptomatic. For early diagnosis to occur, patients may need to be aware of it and seek assessment regularly. People who have risk factors for glaucoma may have a greater awareness of the disease. Methods: Patients presenting to an urban hospital emergency department were surveyed with a brief questionnaire to assess their knowledge of glaucoma. Data was collected about their gender, age, family history of glaucoma and presence of systemic hypertension, diabetes, Raynaud's phenomenon, migraines and myopia. Results: Women (odds ratio 2.3; 95% CI 1.4-3.7; P < 0.01), people who were 40 years or older (odds ratio 2.2; 95% CI 1.1-4.4; P < 0.05) and those who were aware of a family history of glaucoma (odds ratio 15.7; CI 5.5-45.3; P < 0.01) knew significantly more about the disease than others. People with other risk factors did not demonstrate significantly greater knowledge despite 89% of all participants having had a previous eye examination. Conclusion: This information may be useful to predict which patients may know about glaucoma when they present for an eye examination and who should be targeted in public health campaigns.