Effects of tobacco smoking on the human pupil.
Determine the effects of tobacco cigarette or sham placebo-smoking on pupil diameter. Ten non-smokers and 10 tobacco smokers (all healthy, drug free adults) were studied while resting in a comfortable lounger. Tobacco smokers abstained from smoking and all subjects abstained from caffeine-containing products for at least 8 h prior to testing. The smokers each smoked one tobacco cigarette, and the non-smokers each inhaled air through an unlit sham cigarette. Right pupil diameter, heart rate, systolic and diastolic blood pressure were measured before and after sham- or tobacco-smoking in each subject. Pupil size was measured from a colored photograph taken with a Polaroid camera equipped with a high-speed flash with the subject in a standardized, dimly lit quiet room. There was no significant difference in baseline pupil diameter between non-smokers and smokers prior to sham- or tobacco-smoking. After sham- or tobacco-smoking, both non-smokers and smokers showed slight but statistically significant pupillary constriction. Shortly after smoking one tobacco cigarette, pupillary constriction was greater than after sham-smoking.