135 patients were entered into a 28-day randomized double-masked multicentre study comparing the efficacy and short-term safety of lodoxamide 0.1% ophthalmic solution (Alomide--Alcon Laboratories), a mast cell stabilizer, with sodium cromoglycate 2% ophthalmic solution (Opticrom--Fisons Pharmaceuticals) in the treatment of allergic eye disease. Patients given lodoxamide 0.1% showed a significantly more rapid and greater improvement in their signs and symptoms of allergic eye disease than patients given sodium cromoglycate 2%. Both treatments were found to be safe, and side-effect profiles were comparable between the two treatment groups, although the overall incidence of side-effects in this study was found to be less frequent in the lodoxamide-treated group.