According to a British study, smoking cigarettes, or living with someone who does, increases a person's risk of developing a progressively degenerative eye disease known as age-related macular degeneration or AMD.
A Cambridge University team looked at the impact of smoking on AMD, and co-author Dr. John Yates says they found that smokers have an increased risk of losing their sight in old age and the more they smoke the higher the risk.
Of possibly more interest it seems that risk is also higher for those living with smokers, as living with a smoker for five years apparently doubles the risk of the disease and regular smoking triples it,
The risk of developing AMD increases with age and usually develops after a person reaches the age of 50.
It is the leading cause of reduced vision and blindness in many European countries and the US.
The disease affects the central part of the retina, the key area needed for reading and driving, leaving only peripheral vision, but does not always lead to blindness.
Researchers have tried over the years to define the avoidable risk factors in an attempt to reduce the burden of AMD.
Some previous studies have suggested that smoking increases the risk of vision problems, but less is known about the risk of the disease in non-smokers breathing second-hand smoke.
This new research demonstrates that passive smoking can have a similar impact on vision.
Professor Yates says the research demonstrates a clear association between smoking and the disease, and of the many environmental factors investigated in relation to AMD, smoking is the one most consistently found to be associated with increased risk.
The British government has proposed a ban on smoking in England in all workplaces, with the exception of pubs which do not serve food and private members' clubs.
The study is published in the British Journal of Ophthalmology January 2006.