Dark adaptation and recovery from light adaptation: smokers versus nonsmokers.

Because the published data concerning the effects of smoking on visual sensitivity at night are inconsistent, a new study was initiated to obtain ground level comparison data from smoking and nonsmoking Army aviators. Blood samples also were analyzed to compare serum levels of nicotine, cotinine, and carboxyhemoglobin with the visual measures. The present data show no differences in visual sensitivity between smokers and nonsmokers and no significant correlations between the blood and visual measures. The conclusion from these results is that the ability to see the dimmest lights at night is independent of smoking history when scotopic sensitivity is assessed at ground level.