Smoking causes the protective layer between the retina and blood vessels to erode, resulting in poor circulation, irritation and scarring.
Smoking is damaging to the blood supply.
Smoking exposes the body to free radicals which causes cellular damage and can cause poor circulation of nutrients to the retina and lens. Carotenoid levels and vitamin C blood concentrations are substantially reduced. Smoking oxidizes cholesterol, causing fat to build up in the arteries. This leads to heart attack, stroke, and probably macular degeneration. Researchers think smoking contributes to the incidence of some types of cataracts.