Orally inhaled corticosteroid use has been convincingly linked to an increase in the risk of cataracts, although the risk at lower doses in common use remains uncertain. The potential risk of cataracts with the use of nasal corticosteroids is unknown. A matched nested case-control analysis was performed in a population-based cohort of elderly people who had been dispensed medications for airway disease, as identified through a universal drug benefit plan. Inhaled corticosteroid use was associated with a dose-related increase in both the risk of all cataracts and severe cataracts requiring extraction, and the increase in risk of severe cataracts was apparent even at daily doses of </=500 microg. An excess risk with nasal corticosteroids was not apparent for severe cataracts. It is concluded that, among the elderly, even low doses of inhaled corticosteroids are associated with a small but significant excess risk of cataracts requiring extraction. Such an excess risk was not observed with nasal corticosteroids.