Main Entry:

re·frac·tion

Pronunciation:

\ri-ˈfrak-shən\

Function:

noun

Date:

1603

1: deflection from a straight path undergone by a light ray or energy wave in passing obliquely from one medium (as air) into another (as glass) in which its velocity is different2: the change in the apparent position of a celestial body due to bending of the light rays emanating from it as they pass through the atmosphere ; also : the correction to be applied to the apparent position of a body because of this bending3: the action of distorting an image by viewing through a medium ; also : an instance of this

[refraction illustration]