Ocular surface disease encompasses ocular allergy, blepharitis, and dry eye. As many as 30% of patients encountered by ophthalmologists have one of these conditions, yet an incorrect diagnosis is made approximately 50% of the time. This monograph will review the pathophysiology and clinical manifestations of each of these conditions. Therapeutic options for all aspects of ocular surface disease will be discussed, as well as clinical trials examining the efficacy and safety of these treatments. Lastly, advice on the appropriate management of the ocular surface in the surgical setting will be given.