[Physics Form 4] Refraction

• Refraction is the phenomenon exhibited by light when it undergoes a change in speed.
  
  
• Normally, when light travels through two different media of different optical density, it undergoes a change in speed and exhibits refraction.
  
  
• In most cases, refraction is seen as the bending of light or deflection of light from its original direction of propagation.
  
  
• There are two types of refraction:
  
  1. Bending of light towards the normal, which occurs when light moves from a medium of lower optical density to higher optical density.
  2. Bending of light away from the normal, which occurs when light moves from a medium of higher optical density to lower optical density.