A controlled, double-blind comparison of naphalzoline hydrochloride 0.05%, antazoline phosphate 0.5%, a combination of both components and a placebo was performed on 51 ragweed sensitive patients presenting allergic conjunctivitis. Evaluation of response at various times after instillation of medication for lacrimation, conjunctival inflammation, pruritus, photophobia and pain showed naphazoline hydrochloride, antazoline phosphate and the combination product superior to placebo. The combination product was statistically significantly superior for conjunctival inflammation and photophobia. The need for post-challenge treatment with epinephrine hydrochloride was significantly less in those eyes treated with the combination product. demonstrating prophylactic efficacy.