Beach Ball with Fresnel Lenses

A standard plastic beach ball, except... this beach ball is made entirely from plastic fresnel lenses, which give a variety of interesting optical effects.

Fresnel lenses can be made from plastic or glass, and they have the advantage that even a large lens is flat - it does not get fatter in the middle. You would not use them for a precision optical instrument maybe, but one of their uses was in lighthouses, where you need large lenses that do not get impossibly fat (and therefore heavy) in the middle.