Prism

• Prism


  A solid figure encompassed by two opposed, equal, and parallel planes, while the remainder is parallelograms
• Euclid's "The Elements" definition of prism

  C. 300 B.C.E
• Prism


  • Rays of light passing through is bent towards the base
  • An image seen through a prism is displaced towards the apex
  • White light passing towards the prism is dispersed into different colors
  • An eye looking through a prism is deviated towards the apex

  
• Isaac Newton's light spectrum experiment used prisms

  1666

  
• Isaac Newton's experiments on prisms transformed the understanding of light

  
• Dispersion and refraction of light through a glass prism

  1. Light disperses into spectrum of colors

  2. Speed of propagation changes and light bends or refracts

  
• Chromatic aberration


  Refraction of different colors produces a defocusing effect

  
• Newton invented the reflecting telescope in 1668 to solve the problem of chromatic aberration
• Snell's law


  Discovered in 1621 by Willebrord Snell, describes how light waves bend or refract when passing from one medium into another

  
• Huygens' principle


  Proposed by Christiaan Huygens, explains diffraction and the bending of waves around obstacles or the spreading of waves after passing through an aperture

  
• Huygens' principle


  • Every point on a wavefront may be considered a source of secondary spherical wavelets which spread out in the forward direction at the speed of light. The new wavefront is the tangential surface to all these secondary wavelets.

  
• Prisms are prescribed for patients experiencing double vision or having difficulty with binocular vision

  
• Prism base positions


  • BO - Base Out (towards the ear)
  • BI - Base In (towards the nose)
  • BU - Base Up
  • BDn - Base Down
• Fresnel prism


  A thin press-on vinyl sticker with a series of angular grooves (prisms) on one side and a smooth side that attaches to the lens of glasses
• The Fresnel prism was invented by the French physicist Augustin-Jean Fresnel