Smoking is the only environmental factor proven to be linked to macular degeneration by researchers. But other unhealthy habits may "turn on" or activate one of the twenty different genes that have been associated with the condition. For that reason, it is best to avoid smoking. Be sure to exercise daily, eat a healthy diet including lots of fruits, vegetables, and fish. Maintain healthy cholesterol and blood pressure levels as these factors, if problematic, may elevate the risk of developing the disease.