Abstract: A non-invasive method and apparatus for measuring ocular blood flow. Infrared light is directed to the eye fundus by special contact lens. The amount of light energy reflected in detected and recorded. Following the venous injection of a protein bound green dye, the differential light absorption that occurs as the dye passes through the ocular vasculature gives a curve of blood flow which is used to analyze ocular perfusion. Absorption of light in each eye is recorded by a strip chart recorder. The criteria of arrival time, filling, energy absorption change, runoff and symmetry between the two plots are used to judge the ocular flow in each eye.