A form of intervention that involves placing prisms over regular eyeglass frames, which result in a shift of the visual field so that visual targets appear deviated from their original position. When wearing the eye glasses patients initially reach toward the virtual position of the target due to their deviated vision. After repeated treatments with Fresnel prisms, patients can correct their visual positioning and will reach the actual target. For persons with USN, prisms may be used to encourage visual scanning of the neglected hemispace.