She can refract lightwaves to create holographic images. An optical prism is a transparent optical element with flat, polished surfaces that refract light. Thus the wave fronts will refract, changing direction like light passing through a prism. A prism is a transparent optical component with flat surfaces that refract light. However, all these disturbances refract light rays, so they can cast shadows. Condensed water in the air may also refract sunlight to produce rainbows. "Tropo-scatter" happens when water droplets and dust particles refract a VHF/UHF signal over the horizon. The waves converge constructively after they refract and increase the sizes of the waves. Pinhole glasses do not actually refract the light or change focal length. This makes the air refract light to varying extents, affecting the appearance of the horizon. At medium frequencies, this appears to "bend" or refract the signal beyond the horizon. These "internal waves" continue to flow eastward and to refract around coastal features. There is also a yearly regional festival called "Refract", highlighting many different cultural options.