Nature also has the power to heal us. Most medicines are derived, directly or indirectly, from plants. But nature can heal us mentally, too. Scientific studies have shown that natural scenes can reduce stress and anxiety, and have a strong calming and restoring effect. In one experiment, patients recovering from surgery were divided into two groups. One group was put in rooms that overlooked a copse of trees, the others had a view of a plain brick wall. Those with the natural view recovered faster, had fewer complications, and needed fewer painkillers.