Did you know that smoking caused blindness? In the UK, where 20% of young women and 15% of young men smoke, only 2% of those smokers know that their habit increases their risk of age-related macular degeneration (AMD) -- the number one cause of sight loss.

However, when young smokers are aware of this side effect, they fear it more than any other. 90% of young smokers interviewed in a recent survey said they'd give up smoking at the first sign of vision loss, and -- while they rated their fear of lung cancer at only 3 out of 5, the smokers rated sight loss at 4 out of 5.

Smoking and AMD were linked conclusively in 2005, in findings that showed smokers to be twice as likely to develop the condition.