Role of cell-mediated immunity to staphylococci in blepharitis. We studied cell-mediated immunity to staphylococcal antigens in 116 patients with chronic blepharitis and eight normal subjects. Antibodies in tears and blood were measured. Enhanced cell-mediated immunity to Staphylococcus aureus was demonstrated in 46 of 116 patients (40%) in the absence of antibodies to teichoic acid but not among normal subjects. Symptoms of grittiness and morning stickiness were more frequent among patients without enhanced responses. Folliculitis occurred more commonly among patients with enhanced immunity. Marginal keratitis occurred equally among patients with and without enhanced systemic immunity, but patients with enhanced response more commonly required topical corticosteroid therapy. Desensitization to staphylococcal antigens could be investigated as a potential therapeutic approach in selected patients. 