Age-related macular degeneration, a usually untreatable affliction, impairs the vision of an estimated 1.7 million Americans and causes more new cases of blindness than any other ailment among people age 65 or older, according to the government.
Smoking already is blamed for promoting cataracts, another major cause of vision loss.
Cataracts threaten the vision of far more people than macular degeneration but cause much less blindness because most cataract sufferers keep their sight with treatment. The more people smoke and the longer they smoke, the higher their risk of developing macular degeneration, according to two new studies in Wednesday's issue of The Journal of the American Medical Association . Years after quitting, former smokers still faced up to double the risk of getting the condition, the new research found. In advanced macular degeneration, which affects one of every 14 people age 75 or older, the center of the visual field deteriorates, causing a roughly circular area of blindness that grows larger gradually. The deterioration is caused by damage to the macula, the center of the retina, a light-sensitive membrane on the inside back of the eyeball.