An apparatus is disclosed for testing the eye movements of a viewer in response to visual stimuli, such as an advertisement, displayed on a screen. One camera cooperates with a light source to detect eye movements indicated by a light beam deflected off the viewer's cornea. Another camera is placed parallel to the screen and in front of the viewer. A right-angle lens directs light from the screen into the camera. The outputs of the two cameras are combined to superimpose the viewer's eye movements on the images displayed on the screen. A running time starting with the instant the advertisement is exposed to the viewer is also combined with the eye movement and screen presentations.