Now a note about this bit:Purpose.Adult active smoking is a risk factor for dry eye. We hypothesize that passive smoking in children can also produce the same effects.Methods.We included 112 school children presenting with eye discomfort. Assessment of eye dryness and its severity levels depending on symptoms of dry eye, visual symptoms, tear breakup time (TBUT), Schirmer-1 test, and corneal fluorescein staining were done for all of them. Exposure to cigarette smoking was assessed by history-taking and urinary cotinine levels.Results.Dry eye was found in 80/112 children. Passive smoking was documented in 76/112 children. Number of cigarettes to which the child was exposed per day and the duration of exposure to passive smoking were significantly higher in children with dry eye compared to those without. Urinary cotinine, and cotinine/creatinine ratio (CCR) was significantly higher in children with dry eye compared to those without dry eye. Multiregression analysis showed that the most important determinants of dry eye were CCR and number of cigarettes/day.
Conclusion.Passive smoking represents a significant risk factor of dry eye in children comparable to that shown with active adult smoking. Male children are more prone to this effect.
I looked up the smoking rates by country on Wikipedia. Basically, a lot of men (28.7%) smoke, but very few women. Seems reasonable to suppose that the higher rate of male kids being affected is simply because the boys are spending more time with dad than mom.
J Ophthalmol. 2012;2012:130159. Epub 2012 Jul 31.
El-Shazly AA, El-Zawahry WM, Hamdy AM, Ahmed MB.
Department of Ophthalmology, Faculty of Medicine, Ain Shams University, Cairo, Egypt.