Depth of Focus and Visual Recognition of Imagery Presented on Simultaneously Viewed Displays: Implications for Head-Mounted Displays

Abstract

For situations involving simultaneously viewed visual displays.

Detection of visual stimuli on monocular peripheral head-worn displays

“…A third explanation for the differences between detection rates on the simulated vs. real HWD may lie in the differences between the focal plane of the target stimuli on the real HWD and the focal plane of the ongoing task. Winterbottom et al (2007) found that focal depth can affect the detectability of stimuli as well as visual comfort, and that the optimal focal depth should be the midpoint of the range of distances of potential stimuli. These distinctions, however, are for HWD imagery presented directly in the forward field of view, rather than peripherally.…”

“…When people are engaged in mobile work, head worn displays (HWDs) can provide realtime access to information that might otherwise be unavailable or difficult to access. HWDs have been used to augment the worker's view with additional streams of hands-free information in a in a variety of high-tempo contexts such as manual assembly tasks (Büttner, Funk, Sand, & Röcker, 2016), controlling unmanned aircraft (Belenkii, Sverdrup, DiRuscio, & Taketomi, 2017), flight data for pilots (Winterbottom, Patterson, Pierce, Covas, & Winner, 2007;Winterbottom, Patterson, Pierce, & Taylor, 2006), infantry navigation data for soldiers (Glumm, Marshak, Branscome, McWesler, & Patton, 1998) as well as other augmented views of battlefields (Livingston et al, 2011). The intention is that the information provided by the HWD, often adapted to the location or context, will improve the worker's ability to carry out their tasks.…”

Head-worn displays on commercial flight decks

“…However, in practice research indicates that binocular rivalry and eye dominance create difficulties for the observer in focusing on one or the other image at will. 6 The third barrier is perceptual. HWDs allow for a wide variety of display parameters, including focal distance, optical quality, degree of stereopsis, and fields of regard, all of which affect one's ability to perceive and extract information effectively.…”

“…To some degree, HWDs have been associated with ill effects such as nausea and eyestrain. [4][5][6] In their review of thirty years of operational use of a monocular helmet-mounted display, Hiatt and collaborators report that pilots have experienced physical and visual symptoms such as headaches, blurred or distorted vision, and visual illusions that occur while using the display and in some cases persist for some time after use. 5 HWDs have also been found to affect attentional switching between the information displayed on the lens and that available only in the outside world.…”

“…5 HWDs have also been found to affect attentional switching between the information displayed on the lens and that available only in the outside world. 6 A proposed justification for using monocular instead of biocular or binocular units has been that only one eye is presented with Continued on next page…”