A symbol recognition experiment was conducted, with and without PLZT goggles to determine how far apart in color space symbol and background colors must be in order for the symbols to be reliably recognized. Spectral transmittance data showed a reduction of approximately 78 percent in display luminances to the operator wearing PLZT goggles, which was almost uniform across the visual spectrnn. All chromaticities, over the entire CRT display gamut, were found to shift markedly toward green when measured through the goggles. This shift was as much as 0.064 1976 UCS units (for fully saturated blue). No criterion shift (beta) was found between the gogglelno goggle conditions. The measure of sensitivity (d') was significantly reduced (from 3.788, without goggles, to 2.910, while wearing the goggles. The probability of hits also decreased significantly (from 0.945 to 0 . 8 6 3 ) and the probability of false alarms increased significantly (from 0.044 to 0.109) between the no goggle and PLZT cases (all p < 0 . 0 5 ) . The effects of the PLZT goggles on the symbol recognition task were lessened as the symbol-to-background chromaticity distance was increased.These results support the development of specialized color display symbol sets in workplaces where PLZT flashblindness protection is worn by the operator.--