The perception of blur in images can be strongly affected by prior adaptation to blurry images or by spatial induction from blurred surrounds. These contextual effects may play a role in calibrating visual responses for the spatial structure of luminance variations in images. We asked whether similar adjustments might also calibrate the visual system for spatial variations in color. Observers adjusted the amplitude spectra of luminance or chromatic images until they appeared correctly focused, and repeated these measurements either before or after adaptation to blurred or sharpened images or in the presence of blurred or sharpened surrounds. Prior adaptation induced large and distinct changes in perceived focus for both luminance and chromatic patterns, suggesting that luminance and chromatic mechanisms are both able to adjust to changes in the level of blur. However, judgments of focus were more variable for color, and unlike luminance there was little effect of surrounding spatial context on perceived blur. In additional measurements we explored the effects of adaptation on threshold contrast sensitivity for luminance and color. Adaptation to filtered noise with a 1/f spectrum characteristic of natural images strongly and selectively elevated thresholds at low spatial frequencies for both luminance and color, thus transforming the chromatic contrast sensitivity function from lowpass to nearly bandpass. These threshold changes were found to reflect interactions between different spatial scales that bias sensitivity against the lowest spatial grain in the image, and may reflect adaptation to different stimulus attributes than the attributes underlying judgments of image focus. Our results suggest that spatial sensitivity for variations in color can be strongly shaped by adaptation to the spatial structure of the stimulus, but point to dissociations in these visual adjustments both between luminance and color and different measures of spatial sensitivity.

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Laser Eye Protection (LEP) devices selectively alter the spectral environment and affect the ability to identify and discriminate color. Pilots and mariners must wear LEP for their safety and still make decisions based on colored lights and objects. These abilities can be compromised with LEP. Determining the level of degradation caused by LEP remains challenging; LEP devices are not uniform in construction and results from laboratory tests may be poor indicators of actual user performance. In addition, performance deficits in the maritime and aviation environment can be exacerbated by cognitive distracters. However there is little known about the interaction of attentional effects with color performance deficits from the use of LEP. Several different mathematical models of color vision were utilized to model and predict color vision performance. Spectral reflectance or transmission was measured and placed into equations utilizing color matching functions of the standard observer. These values were then translated into different color spaces. These results were compared with actual performance. Results for modeling indicate that models that take into account color zone shifts, rather than color shifts are more accurate, and that models cannot yet account for all aspects of color vision performance such as when cognitively distracted.

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