The geologic structure can be imaged from the refracted/reflected waves. Supposedly, "eloptic" emanations are refracted by the prism at different angles depending on the material. Caustics are a lighting effect of reflected and refracted light moving through a medium. The only light reflected from the lunar surface has been refracted by Earth's atmosphere. Glories arise due to wave interference of light internally refracted within small droplets. During propagation, waves can be reflected, refracted, or attenuated by the medium. This appearance was due to silk's prism-like shape/structure, which refracted light from every angle. Light entering the eye is refracted as it passes through the cornea. Its atmosphere is visible through telescopes by the halo of sunlight refracted around it. The light is refracted at the surface of the raindrop. This indirect sunlight has been refracted as it passed through Earth's atmosphere. He was also aware that the incident and refracted rays were interchangeable. He concluded that light could not be refracted through a lens without causing chromatic aberrations. When electromagnetic radiation passes through the atmosphere, it is refracted (or bent). When light travels from one medium to another it is refracted.