Since its introduction in ophthalmology more than a decade ago, the use of optical coherence tomography (OCT) has blossomed in clinical practice. The technology has proven an essential diagnostic tool for assessing retinal diseases because of its ability to relate cross-sectional images of the retina and perform quantitative analysis of retinal morphology. This collection of content reviews the evolution of OCT, its basic science and principles, as well as its primary applications in the detection of retinal disorders.