Perceptual issues in optical-see-through displays

Optical see-through devices enable observers to see additional information embedded in real environments. There is already some evidence of increasing visual load in respective systems. We investigated visual performance when users performed visual search tasks or dual tasks only on the optical see-through device, only on a computer screen, or switching between both. In spite of having controlled for basic differences between both devices, switching between the presentation devices produced costs in visual performance. The assumption that these decreases in performance are partly due to differences localizing the presented objects was confirmed by convergence data.