Definition: A scientific term for the way a ray of light changes direction as it crosses the boundary between two substances with different properties, for example glass and air or water and air. Think of the way a stick appears to 'bend' when put in water; this is caused by the direction of the light being refracted at the water/air surface.

See also:
• How to Paint a Water Droplet

<Back to Last Page>     <Full Glossary>