There are only three possible interactions. If the light enters and exits the surface of the substance in relatively
undisturbed fashion, then the substance is referred to as transparent. If the light can enter and exit the surface of the
substance, but in a disturbed and distorted fashion, then the substance is referred to as translucent. If the light cannot
even penetrate the surface of the substance, then the substance is referred to as opaque. Many substances that
are transparent can easily contain flaws and distortions that will limit a light beam's travels through a substance and
make it translucent .