The first ray, shown above, begins from the tip of the image and travels to the lens parallel to the principal axis. The second ray also leaves from the tip of the object, and travels straight through...The first ray, shown above, begins from the tip of the image and travels to the lens parallel to the principal axis. The second ray also leaves from the tip of the object, and travels straight through the center of the lens. In the Contact Lens simulation below, the Lens Slider allows you to choose between a converging (convex) contact lens and a diverging (concave) contact lens.
