Snell laws of refraction

Snell laws of refraction

[′snel ′lȯz əv ri′frak·shən]
(optics)
When light travels from one medium into another the incident and refracted rays lie in one plane with the normal to the surface; are on opposite sides of the normal; and make angles with the normal whose sines have a constant ratio to one another. Also known as Descartes laws of refraction; laws of refraction.