Despite the advent of remotely operated and autonomous targeting systems, human (direct) vision is still critical for the successful performance of many tasks on the battlefield. Since high intensity light sources have the potential to generate a variety of disturbing visual effects, ranging from short-term disruption to lasting eye damage, they may offer a simple and cost-effective method to deny operators the possibility to successfully fulfill their tasks. Here we describe the full range of different effects that result from stimulation of the human visual system with high intensity (visible) light, and their associated potential operational impact. To systematically investigate the capability of high intensity light sources to disturb human vision and degrade human task performance we designed test protocols involving a range of military relevant tasks. The effectiveness of optical countermeasures is quantified both through their impact on task performance and through subjective reports on the experienced level of discomfort. We also derived a model that predicts normal driving behavior during exposure to a high intensity light source. These predictions can be directly related to operational requirements and can thus be used to assess the operational effectiveness of optical countermeasures. Unexpectedly, the results from our tests indicate that severe light insults have only very limited effect on human performance, even when the associated levels of visual discomfort are extremely high. Together with the limited window of operation (only during darkness) and other operational limitations (e.g., the difficulty of pointing a beam straight at the adversary) these findings question the effectivity of high intensity light sources as robust countermeasures against human operators. Further research should focus on the stimulus characteristics and methods of delivery to optimize the effectiveness of these countermeasures.

Date Published: 7 October 2014
PDF: 16 pages
Proc. SPIE 9251, Technologies for Optical Countermeasures XI; and High-Power Lasers 2014: Technology and Systems, 92510G (7 October 2014); doi: 10.1117/12.2066125

Published in SPIE Proceedings Vol. 9251:
Technologies for Optical Countermeasures XI; and High-Power Lasers 2014: Technology and Systems
David H. Titterton; Willy L. Bohn; Harro Ackermann; Mark A. Richardson; Robert J. Grasso, Editor(s)