This demonstration initializes with a concave mirror and an object represented by a green arrow. Two rays are traced to show the reflection of the object. A small point moves along each ray to highlight the direction of light travel. Real rays are indicated by solid lines, and virtual rays (rays that appear to pass through the mirror surface) are drawn with dotted lines.
Three important points are also highlighted: the center of curvature, the focus, and the vertex. A label for each point appears when you point at it. The focus and center of curvature may be moved to alter the shape of the mirror.
A toggle button has been provided to switch between a concave mirror and a convex mirror.