Illustrate the function of convex and concave optical lenses on your PC.
Lenses are classified by the curvature of these two surfaces. A lens is biconvex (or just convex) if both surfaces are convex, likewise, a lens with two concave surfaces is biconcave (or concave). If one of the surfaces is flat, the lens is termed plano-convex or plano-concave depending on the curvature of the other surface. A lens with one convex and one concave side is termed convex-concave, and in this case if both curvatures are equal it is a meniscus lens. Optical Lenses illustrates the function of convex and concave optical lenses. Both the size and the distance of the object and the focal length may be adjusted by the user.
I was hoping it would be something that would get into the technical information about compound lenses. Maybe it would entertain a child for 3 or 4 minutes if you narrated it for them.