In human vision, the depth of focus (DOF) blur is important to perceive single binocular vision. Unfortunately, conventional stereoscopic displays cannot provide a natural DOF blur effect. Synthetic DOF blur that simulates the natural DOF blur effect could be useful for reducing the visual discomfort in stereoscopic displays. However, the incorrect introduction of artificial blur in the image might also have negative effects. This paper proposes a selective DOF blur technique that is applied only to local regions that induce high visual discomfort but are less visually important. We employ a visual importance analysis to obtain reasonable estimates of the areas/objects that are likely to be attended using saliency maps. After identifying the regions likely to cause discomfort because of excessive relative disparity, we apply low-pass filtering for the less-salient neighboring pixels of the discomfort regions. We demonstrate that the DOF blur simulation for less important background regions that induce visual discomfort is helpful in reducing the visual discomfort in stereoscopic viewing.