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Abstract
The predominant factor limiting the detectability of distant targets is veiling due to atmospheric scattering, known commonly as haze. It has been suggested that yellow filters (in this case, the macular pigments, MP) that absorb this haze could extend visual range. This hypothesis was tested on 27 subjects with a wide range of MP optical densities. Visibility was measured by varying the amount of simulated blue haze needed to veil a sine-wave grating (7.5 cyc/deg). Visibility for this target under xenon light and shortwave deficient (SWD) light was also assessed. MP was significantly related to energy at threshold for both haze (r = 0.59, p < 0.01) and xenon (r = 0.60, p < 0.01) backgrounds, but not the SWD background. Thus, subjects with higher levels of MP could withstand more light before losing sight of the target, which is consistent with previous modeling by Wooten and Hammond (2002).