On the basis of clinical and histologic examinations, wrinkles in the "crow's foot" area were shown to be caused by actinic exposure, not by cigarette smoking. By including black patients in our study, the factor of sunlight exposure was effectively controlled; in these patients (smokers and nonsmokers), facial wrinkles were absent. Histologic preparations from white smoking and nonsmoking patients, with and without wrinkles, showed changes only of actinic elastosis.
Allen HB, Johnson BL, Diamond SM. Smoker's Wrinkles?. JAMA. 1973;225(9):1067-1069. doi:10.1001/jama.1973.03220370019004