Abstract: Apparatus and method for testing the visual response of a patient is disclosed. The apparatus comprises image generation means (16), image presentation means (12), and detection means (13,14). The image generation means (16) and image presentation means (12) are arranged, in use, to generate and present an image before an eye of the patient at variable predetermined intensity levels. The detection means (13,14) is arranged under the control of a controller (11) to detect a stimulus response to the presented image occurring in the brain of the patient and to display an image of the response of the patient's eye on a monitor (15).