light and the eye

• the law of reflection says the angle of incidence is equal to the angle of reflection
• refraction occurs when a wave changes speed as it passes from one region to another
• if light bends towards the normal the angle of refraction is less than the angle of incidence
• if light bends away from the normal the angle of refraction is greater than the angle of incidence
• types of reflection

  mirror, specular and diffuse
• two types of lenses

  converging - convex

  diverging - concave
• converging (convex) lenses make a parallel beam of light converge to a focus
• diverging (concave) lenses make a parallel beam of light spread out so it appears to come from a focus