Another good reason to stop smoking: Macular degeneration. It's the number one cause of blindness in people above the age of 60 and can stem from cigarette smoking.

Smoking more than doubles the chances you'll acquire macular degeneration and former smokers are at risk just like current smokers. There are other risk factors for macular degeneration -- like age, family history, obesity, exposure to sunlight, low levels of nutrients, and cardiovascular disease -- but smoking is the single most preventable cause of this eye disorder.

Degeneration of the macula causes blurred central vision or a blind spot in the center of your visual field. The first sign of the condition may be a need for more light when doing close-up work. Fine newsprint and street signs may become harder to read and while these symptoms may develop gradually, they often lead to severe vision loss in one of both eyes.

A comprehensive eye exam can help determine whether or not you have some degree of macular degeneration. Quitting your smoking habit can help ensure you don't ever get it.