The Upside Down Sphere

If the sphere is treated like a thin-lens, magnification equals image divided by object, or -1.33, a number that indicates the object will appear enlarged and inverted. If the sphere is treated like a prism, light travelling parallel to the center line and entering near the top of the prism is bent closer to the edge of the prism than light travelling parallel to the center line and entering near the center of the prism. This is called spherical aberration and creates the distorted, blurred appearance of the image.