In this review we report the distribution and functional significance of growth factors in the eye. Representatives of the major growth factor families are found in the eye: fibroblast growth factor, insulin and insulin-like growth factor, transforming growth factor-beta, platelet-derived growth factor, nerve growth factor, epidermal growth factor and colony-stimulating factor. There are numerous examples of their actions on ocular tissues in vitro and in some cases in vivo. The findings presented clearly illustrate that a growth factor can elicit different responses depending on the context of its action; the cell type involved, the concentration of the growth factor and the presence or absence of other growth factors can all influence the cellular response both quantitatively and qualitatively. The results of these studies in the eye are of general significance to our understanding of the role of growth factors in biological processes.