OBJECTIVES: The objective of the present study is to estimate the prevalence of treatment with intraocular pressure (IOP) lowering topical medication in subjects aged 40 years or more in continental France, and to describe the type of therapy, the compliance and quality of life of the treated subjects. METHODS: This is a telephone survey performed in general population on a representative sample of 5726 subjects during the year 2004. Subjects treated for glaucoma or HTO were defined as those: declaring using eye drops for more than one month and 1) citing one of the 52 registered IOP-lowering topical medications, and/or 2) declaring that they were taking the eye drops for glaucoma or ocular hypertension (OHT). Quality of life was measured using the GlauQOL-17 questionnaire. RESULTS: Globally, 237 subjects (4.1 %) corresponded to this definition. The prevalence increased with age, from 0.7 % in subjects aged 40-44 years to 10.6 % in those aged 80 years or more. Beta-blockers (49.5%) and prostaglandins (37.4%) were the more frequent treatments, followed by carbonic anhydrase inhibitors (15.3%), sympathomimetic mydriatics (5.7%) and myotics (1.3%). Compliance was not total for 39 % of the patients (22 % of those treated with one-daily dosing). Those subjects showed lower values in several dimensions of the quality of life. This is a new way to estimate the GPAO and HTO prevalence. This allowed to give a useful approximation to professionals involved in ocular diseases medical, economical and societal management. CONCLUSION: On the basis of this first nationwide study, it can be estimated that the prevalence of subjects treated with IOP-lowering topical medications is about 1.2 million in France. Number of daily doses appear to influence compliance.