An injection/circulation-timing switch was developed to simply and precisely initiate the timing unit of the fundus camera for angiographic documentation. After starting the timer, the switch, mounted on the syringe used for injection of the tracer material, subsequently provides documentation of the total elapsed time of injection. Such quantitative data can enhance the evaluation of angiographic results and contribute to their universal comparability when combined with such qualitative data as injection location and total injectate.