OBJECTIVES: The purpose of this study was to examine the economic and quality of life (QoL) impact of seasonal allergic conjunctivitis (SAC)in Oxfordshire, England. METHODS: The inclusion criteria for cases were that participants: 1) experienced itchy, bloodshot and watering eyes at some time between February and August every year since 1999, and 2) considered it likely that this was in response to seasonal allergens. Controls were drawn from the same sources and were age and sex-matched to cases. Participants completed the EQ-5D Health Questionnaire, the Rhinoconjunctivitis Quality of Life Questionnaire, the National Eye Institute (US) Visual Functioning Questionnaire 25, and a specially developed Health Economic and Demographic Questionnaire. RESULTS: Most participants in both groups were female (67.5% in SAC and 70% in control group, P = 0.565). Weekly earnings were lower in the SAC group (P<0.001), as the SAC group also worked fewer hours per week (P<0.001). Participants with SAC also experienced a greater degree of pain and discomfort as measured by the EQ-5D (P = 0.018) and a lower perception of their health status using the EQ-VAS (P = 0.039). Statistically significant differences between both groups were detected in all domains of the VFQ-25, except general and colour vision, although differences were thought to be clinically significant only for the ocular pain domain. The RQLQ scores were also all found to differ significantly between groups (P<0.001). The total of both the public health care and private out-of-pockets costs of SAC in our study population ranged on average between £64.61 for a pensioner to £142.29 for a person with SAC in paid employment. CONCLUSIONS: SAC is a costly, highly prevalent, chronic condition associated with significant reductions in both ocular and general quality of life, as well as ongoing out-of-pocket expenses and health care costs.