A method for tracking the optical axis of an eye, comprising the synchronization of a light wave provided by a light source with a video signal captured by a video camera including images made up of interlaced frames, wherein said video camera and said light source are carried by a support element adapted to be adjusted to the head of a patient so as to capture images of the eye of the patient using the video camera, said light source being arranged near the center of the video camera lens in order to determine a Purkinje point, said method being characterized in that it comprises the next steps of: reception of the video signal by a housing to control the ignition of the light source; extraction by housing processing means of a frame synchronizing signal by identification of the even and odd frames constituting the video signal; determination by the housing processing means of a signal for synchronizing the images by detection of the even and odd images constituting the video signal, the determination of the synchronizing signal for the even and odd images constituting the video signal being obtained from the frame synchronizing signal extracted from the video signal by the housing processing means; generation of a control signal for the light source by the housing processing means from a logical combination between the signals for synchronizing the frame and for synchronizing the images, suitable to cause the ignition of the light source only for the duration of only one frame and this, for one among two images, and emission of the control signal to a module for supplying the light source able to control the ignition and the extinction of the light source according to the control signal, and wherein the video signal is retransmitted by the housing to a storage means to be recorded therein, said recorded signal being submitted to a processing wherein a subtraction point-to-point of the luminosity value between two successive images is carried out in order to locate, in a scene, the position of the representation of the light source. reception of the video signal by a housing to control the ignition of the light source; extraction by housing processing means of a frame synchronizing signal by identification of the even and odd frames constituting the video signal; determination by the housing processing means of a signal for synchronizing the images by detection of the even and odd images constituting the video signal, the determination of the synchronizing signal for the even and odd images constituting the video signal being obtained from the frame synchronizing signal extracted from the video signal by the housing processing means; generation of a control signal for the light source by the housing processing means from a logical combination between the signals for synchronizing the frame and for synchronizing the images, suitable to cause the ignition of the light source only for the duration of only one frame and this, for one among two images, and emission of the control signal to a module for supplying the light source able to control the ignition and the extinction of the light source according to the control signal, and wherein the video signal is retransmitted by the housing to a storage means to be recorded therein, said recorded signal being submitted to a processing wherein a subtraction point-to-point of the luminosity value between two successive images is carried out in order to locate, in a scene, the position of the representation of the light source.