The human eye is never still; the eyes move even when a person gazes steadily at an object. These involuntary movements of the eye are minuscule, and have been extensively studied with respect to their size, frequency and how they change according to the object being fixated. A useful method for studying these eye movements is to render the retinal image steady in relation to the light receptors--the stabilized image technique. After an initial period of clear visibility, the image gradually fades and disappears, despite its constant presence on the retina. Understanding how and why retinally stabilized images disappear is important to clarifying how the visual system detects and adapts to steady and moving images. The present research involves development of a quantitative model of stabilized-image adaptation, relating these adaptation processes to known theories of light adaptation. Three areas of research are involved: The spatial aspects of the adaptation process are studied in detail; the response of the adaptation process to uniform lights is measured; and the use of colored stimuli should help determine the physiological location of the adaptation process, itself. The development of a general model from this research will provide a framework within which the effect of adaptation to any spatio-temporal signal can be assessed, including those generated by normal motions of the eye.
