Effects of image distance and seat inclination on the line-of- sight angle

The line-of-sight angle (LOSA) was investigated for a simple tracking task. The distance from the eyes of the subject to the image was varied through the use of optical lenses. The subject was seated in a chair with 5 different back angles: 90 degrees, 111.6 degrees, 125 degrees, 158.5 degrees, and 177.1 degrees. No significant difference in the selection of LOSA was found between image distances of .5 meters, 1 meter, 2 meters, and infinity. The subjects' selection of LOSA was affected by the change in seat inclination angles.