Optical pattern. Computer model of patterns formed by refraction. This is similar to the wavy pattern formed on the bottom of a swimming pool. In the swimming pool, the light passes through one wavy surface before the resulting pattern is seen on the bottom of the pool. In this model, the light has passed through two wavy surfaces and the pattern is more complex. The pattern is an example of caustics, the patterns arising when overlap is observed. Here, refracted light is concentrated in certain areas, creating these patterns. This model was created as an artwork by Professor Eric Heller.