Four million people die annually because of diseases caused by tobacco smoking, one person every 8 seconds. Tobacco smoking is the main cause of diseases worldwide and if the current tendency is maintained, by 2020, smoking will kill more persons than AIDS, tuberculosis, maternal mortality, car accidents, suicides and murder, as 35 % of the adults worldwide smoke. The risk for a smoker to die because of smoking is 50 %.

The habit has been associated with over 50 issues, over 25 being life-threatening, like lung cancer, heart attack, stroke, chronic bronchitis, emphysema, and other lung diseases. Pregnant women put the life of their unborn children at risk by smoking, increasing the risks of having a spontaneous abortion, give birth to a still child (or the infant dies soon after birth. But other issues also deeply affect life quality, like impotence, sterility in both women and men, wrinkles, yellowed skin, digits and teeth, sagged breasts, bad breath, taste and smell loss, vulnerability to skin diseases, coughing, accelerated breath or increased baldness. Now add another one: blinding.

Smoking seems to boost long-term risk and progression of the age-related macular degeneration (AMD), the main cause of blindness in elders, as revealed by a new research published in Archives of Ophthalmology. This effect could be induced through several pathways: by plummeting the levels of antioxidants, slowing down ocular blood flow or destroying the visual retinal pigments.

The team at the University of Wisconsin School of Medicine and Public Health, Madison, carried out its research on 4,926 subjects, aged 43 to 84 in 1987 to 1988. Their presence and state of AMD were assessed in 1988 to 1990 and then every five years for the next 15 years.

When the follow up started, 21 % of the men and 18 % of the women were smokers. This category had a 47 % higher probability of developing early AMD (the least severe stage of this condition) and at a younger age (69.2 years) compared to former smokers (72.3 years) and subjects who never smoked (74.4 years). Smoking also caused a cumulative progression of AMD over the 15 years of the follow up.

"Smoking appears to be related to the incidence and progression of AMD in our population. This has important health care implications, because early AMD is associated with an increase in the risk of developing late AMD (blindness) and smoking behavior is modifiable," the authors wrote.