refraction and lenses

Refraction – view of background pattern through glasses

Refraction – When light moves from one substance to another it changes speed and direction. That change in direction is called refraction.

Refraction and Lenses (images) – Light refracts as it passes from one material to another. It occurs because light changes speed as it passes into a new material. This change in speed is accompanied by a change in direction.

  • Light traveling from the water to your eye refracts or bends as it passes from the water to the air.


  • converging lens – gathers light from a distant point and converging it to a single point in space. These lenses are characterized as being thickest across their mid-section and thinnest at their outer edges. For example, a magnifying glass
  • diverging lens takes light from a single point in space and diverges it as it passes through the lens. These diverging lenses are characterized as being thinnest across their mid-section and thickest at their outer edges. Prescription eyeglasses used to treat nearsightedness (myopia) are diverging lenses.
Diagram of a dispersion prism
  • prism – breaks a beam of visible light into its basic colors – red, orange, yellow, green, blue, indigo, and violet (ROY-G-BIV). A prism is made up of two planar surfaces at an angle. It uses the slower speed of light in glass to refract the light twice. Because of the different wavelengths of light, each color is refracted a different amount. When the light ray leaves the prism, it speeds up again (entering the air) and refracts a second time. That second dispersal creates the colorful spectrum of colors.

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