Abstract
Purpose:
Handheld lasers have become commonplace, examples include laser games and hobbyist targeting devices. Unfortunately these lasers are at times used maliciously against commercial aircraft. Misuse has risen at an alarming pace with the Federal Aviation Administration reporting 3500+ events in 2011 alone; thus, laser eye protection (LEP) for aircrew is a growing concern. Aircrew LEP requires careful consideration for integration with avionics and multifunction displays (MFD) which are heavily dependent upon the accurate perception of color. The perception of color, mediated by cone photoreceptors, is altered by conventional LEP due to incongruent impact upon short, medium and long-wavelength sensitive cones. The objective of this study is to compare a color-balanced LEP design, one which preserves the weighting of spectral transmission to cone subtypes, with conventional LEP on tests of color discrimination used as predictors of MFD integration and user acceptance.
Methods:
15 color-normal subjects completed color identification tasks with the Farnsworth Munsell-100 and an 8-hue simulated MFD color identification test without and with a color-balanced LEP and a luminance matched neutral density (ND) filter. Results were compared to predictive models of color identification errors (E94, Color-Zone Border Analysis and ΔEu’v’) and like data collected previously for two conventional LEP.
Results:
FM-100 total error scores exceeded 80 for conventional and color-balanced LEP designs, the threshold for impaired discrimination, and were significantly higher than null and ND filter conditions. Color identification was markedly improved on the 8-hue MFD test for the color-balanced design vs. conventional LEP, statistically outperforming on five hues and producing a minor decrement for one. Global error rate across 8 hues was ~40% for conventional designs and 7% for cone-balanced. E94 calculations were ~10 for conventional vs. 8 for the cone balanced LEP design also predicting improved hue discrimination.
Conclusions:
A color-balanced LEP design demonstrates better integration for key multi-function display hues when compare with conventional LEP. Both conventional and color-balanced LEP, by virtue of selectively blocked wavelengths, produce higher total error scores with the Farnsworth Munsell-100; however, this test may not be the best predictor of user acceptance for LEP in cockpit integration.
Keywords: 578 laser •
641 perception