Effects of a laser-induced temporary scotoma on target acquisition performance

Lasers commonly used in industry and the military are increasingly being recognized as possible hazards to vision and visually guided tasks. This study examined the effects of laser-induced visual loss on target acquisition performance. An argon laser was used to produce a temporary central scotoma. Observers searched for variable-contrast aircraft that were embedded in backgrounds of differing complexity. The laser exposures increased acquisition times 2 to 12 times over baseline levels, indicating that the degree of visual deficit was task dependent. Acquisition time increased as background complexity increased and target contrast decreased. However, target motion facilitated acquisition performance and mitigated the laser effect. Although contrast had a systematic effect on acquisition performance, it was clear that factors other than contrast contributed to target visibility. Other factors that may have affected visibility included distractors and masking effects introduced by the structured backgrounds.