The number of cases of primary open angle glaucoma (POAG) in England and Wales is estimated to increase by a third over the 20 years to 2021, and then continue upwards at a similar pace to 2031. The estimates are based on official population projections, organised by 5-year age groups, together with an age-specific prevalence curve for POAG derived from the results of 11 epidemiological prevalence surveys. To cope with additional pressures, a thorough reappraisal of the present system for detection, referral, diagnosis, treatment and monitoring of the disease is likely to be required.