physical phenomenon - a natural phenomenon involving the physics of matter and energy

optical aberration, aberration, distortion - an optical phenomenon resulting from the failure of a lens or mirror to produce a good image

absorption band - a dark band in the spectrum of white light that has been transmitted through a substance that exhibits absorption at selective wavelengths

diffraction - when light passes sharp edges or goes through narrow slits the rays are deflected and produce fringes of light and dark bands

incidence - the striking of a light beam on a surface; "he measured the angle of incidence of the reflected light"

optical illusion - an optical phenomenon that results in a false or deceptive visual impression

pleochroism - the phenomenon of different colors appearing when certain crystals are viewed from different directions

polarization, polarisation - the phenomenon in which waves of light or other radiation are restricted in direction of vibration

parallax - the apparent displacement of an object as seen from two different points that are not on a line with the object

Tyndall effect - the phenomenon in which light is scattered by very small particles in its path; it makes a beam of light visible; the scattered light is mainly blue