Selenium is an essential microelement required as a nutrient by human organism to perform important biological functions, mainly in the form of selenocysteine. It plays an important role in improving human immunity and the myocardial nutritional blood flow, and preventing oxidative stress. Various ocular diseases are closely associated with selenium and selenoprotein due to the presence of high concentration of selenium. This article mainly aims to review the present research advance of biological functions of selenium and selenoprotein in ocular diseases, and provide some valuable reference for deeper study of selenium in human eyes.