AbstractThe maintenance of normal retinal structure and function depends on a tightly regulated environment. This requires intact blood‐retinal barriers as well as an efficient regulation of blood flow and delivery of oxygen and metabolic substrates to the retinal tissue. Thanks to the development of noninvasive techniques allowing the quantitative assessment of retinal hemodynamics in the human eye, much progress has been achieved in recent years in the understanding of retinal blood flow regulation and the mechanisms involved in this physiological process. Retinal blood flow is regulated by the interaction of myogenic and metabolic mechanisms through the release of vasoactive substances by the vascular endothelium and retinal tissue surrounding the arteriolar wall. This regulation is achieved by adaptation of the vascular tone of the resistance vessels to changes in the perfusion pressure or metabolic needs of the tissue. This adaptation occurs through the interaction of multiple mechanisms affecting mainly the arteriolar smooth muscle cells. These mechanisms, which involve the close interaction between nitric oxide, lactate and arachidonic acid metabolites released by the neuronal and glial cells, optimize blood flow according to the metabolic needs of the tissue. Impairments of structure and function of the retinal neural tissue and endothelium during the evolution of ischemic microangiopathies affect the interaction of the retinal metabolic pathways and alter blood flow regulation. Assessing retinal blood flow and its response to various physiological stimuli and the mechanisms mediating and modulating these responses has provided important insight into these pathological processes, which lead to severe losses of vision.