Information related to adverse drug effects caused by ocular medications and ocular adverse effects of systemically administered drugs has increased over the last several decades. Here we review the medical literature over the last four decades to both quantitatively and qualitatively determine the adverse effects of ocular drugs and ocular toxicity of non-ocular drugs. A systematic bibliographic review of the literature was performed with the following terms: "drug treatment", "drug therapy", "ocular adverse effects", "ocular side effects", "ocular toxicity", "systemic side effects", "systemic adverse effects", "systemic toxicity", "ocular drug" and "ophthalmic drug" using the Boolean operators or, and, not. Searches focused on: (1) Ocular side/adverse effects of ophthalmic drugs; (2) Ocular side/adverse effects of systemic drugs; (3) Systemic side/adverse effects of ophthalmic drugs. PubMed was used to perform searches. Limits included: species, human and field tag, abstract/title, dates from 01/01/1971 to 31/12/2010. A sub-selection of references was made by discarding articles that were irrelevant for the topics listed above. Adverse effects of alpha2-adrenergic agonists, beta-adrenergic antagonists, quinine derivatives and antituberculosis agents appear in the literature throughout the period of the review. Adverse effects of newer drugs such as amiodarone, phosphodiesterase 5 inhibitors, antiepileptics, tamoxifen, and its interactions have been published principally in the last two decades. It is imperative for patient safety that knowledge of the adverse effects of drugs on the eye whether topically or systemically administered, and the possible systemic effects of drugs given as ophthalmic medications be emphasized to clinicians.