Visual Interference with a Transparent Head Mounted Display

Potential perceptual problems that may occur with monocular wearable displays are binocular rivalry and visual interference. We report the results from an experiment with a monocular wearable showing that text becomes increasingly difficult to read as the background becomes more complex. Indeed subjects adopted strategies to avoid the visually complex backgrounds and thereby minimize the interference

Rivalry and interference with a head-mounted display

Perceptual factors that affect monocular, transparent (a.k.a see-thru ) head-mounted displays include binocular rivalry, visual interference, and depth of focus. We report the results of an experiment designed to evaluate the effects of these factors on user performance in a table look-up task. Two backgrounds were used. A dynamic moving background was provided by a large screen TV and an untidy bookshelf was used to provide a complex static background. With the TV background large effects were found attributable to both rivalry and visual interference. These two effects were roughly additive. Smaller effects were found with the bookshelf. In conclusion we suggest that monocular transparent HMDs may be unsuitable for use in visually dynamic environments. However when backgrounds are relatively static, having a transparent display may be preferable to having an opaque display

Driving While Reading Using Google Glass Versus Using a Smartphone: Which is More Distracting to Driving Performance?

Using a phone while driving leads to distraction and impaired driving performance. When reading text on a phone, the act of looking away from the road could cause driving impairment. Wearable displays like Google Glass might reduce the visual impairment caused by looking away, even if they do not overcome other factors contributing to impaired driving. However, such devices could also increase impairment by giving drivers the mistaken impression that they can pay attention to both the display and the road simultaneously or impair visual processing by superimposing visual information in the driving scenes. We compared driving performance in a simulated naturalistic driving task while drivers read text on Google Glass or on a smartphone. As expected, reading on Google Glass and the smartphone both impaired driving performance by increasing lane variations, but drivers using Google Glass showed less lane variation compared to smartphone users. To the extent that these metrics reflect better driving performance, Google Glass might somewhat reduce the costs of reading text while driving. Keywords: Driver distraction; Tactical vehicle control; Google Glass; Cellphon

Methods and systems for detection of ice formation on surfaces

A system for detecting ice formation on metal, painted metal and other material surfaces can include a transparent window having an exterior surface upon which ice can form; a light source and optics configured and arranged to illuminate the exterior surface of the window from behind the exterior surface; and a detector and optics configured and arranged to receive light backscattered by the exterior surface and any ice disposed on the exterior surface and determine the thickness of the ice layer. For example, the system can be used with aircraft by placing one or more windows in the wings of the aircraft. The system is used for a novel optical method for real-time on-board detection and warning of ice formation on surfaces of airplanes, unmanned aerial vehicles (UAVs), and other vehicles and stationary structures to improve their safety and operation

Helicopter flights with night-vision goggles: Human factors aspects

Night-vision goggles (NVGs) and, in particular, the advanced, helmet-mounted Aviators Night-Vision-Imaging System (ANVIS) allows helicopter pilots to perform low-level flight at night. It consists of light intensifier tubes which amplify low-intensity ambient illumination (star and moon light) and an optical system which together produce a bright image of the scene. However, these NVGs do not turn night into day, and, while they may often provide significant advantages over unaided night flight, they may also result in visual fatigue, high workload, and safety hazards. These problems reflect both system limitations and human-factors issues. A brief description of the technical characteristics of NVGs and of human night-vision capabilities is followed by a description and analysis of specific perceptual problems which occur with the use of NVGs in flight. Some of the issues addressed include: limitations imposed by a restricted field of view; problems related to binocular rivalry; the consequences of inappropriate focusing of the eye; the effects of ambient illumination levels and of various types of terrain on image quality; difficulties in distance and slope estimation; effects of dazzling; and visual fatigue and superimposed symbology. These issues are described and analyzed in terms of their possible consequences on helicopter pilot performance. The additional influence of individual differences among pilots is emphasized. Thermal imaging systems (forward looking infrared (FLIR)) are described briefly and compared to light intensifier systems (NVGs). Many of the phenomena which are described are not readily understood. More research is required to better understand the human-factors problems created by the use of NVGs and other night-vision aids, to enhance system design, and to improve training methods and simulation techniques