optical phenomenon(noun)

a physical phenomenon related to or involving light

Optical phenomenon

An optical phenomenon is any observable event that results from the interaction of light and matter. See also list of optical topics and optics. A mirage is an example of an optical phenomenon. Common optical phenomena are often due to the interaction of light from the sun or moon with the atmosphere, clouds, water, dust, and other particulates. One common example is the rainbow, when light from the sun is reflected and refracted by water droplets. Some, such as the green ray, are so rare they are sometimes thought to be mythical. Others, such as Fata Morganas, are commonplace in favored locations. Other phenomena are simply interesting aspects of optics, or optical effects. The colors generated by a prism are often shown in classrooms, for instance.