Tobacco smoke contains a range of toxins including carbon monoxide
and cyanide. With specialized cells and high metabolic demands, the
optic nerve and retina are vulnerable to toxic exposure. We examined
the possible effects of smoking on color vision: specifically, whether
smokers perceive a different pattern of suprathreshold color
dissimilarities from nonsmokers. It is already known that smokers
differ in threshold color discrimination, with elevated scores on the
Roth 28-Hue Desaturated panel test. Groups of smokers and nonsmokers,
matched for sex and age, followed a triadic procedure to compare
dissimilarities among 32 pigmented stimuli (the caps of the saturated
and desaturated versions of the D15 panel test). Multidimensional
scaling was applied to quantify individual variations in the salience
of the axes of color space. Despite the briefness, simplicity, and
“low-tech” nature of the procedure, subtle but
statistically significant differences did emerge: on average the
smoking group were significantly less sensitive to red–green
differences. This is consistent with some form of injury to the optic
nerve.