Lens

• There are two types of Lens.

  
  

  - Concave

  - Convex
• Convex (Converging) Lens, refracts light inwards.
• Concave (Diverging) Lens, refracts light outwards.
• On both Lens the principal focus is on both sides.
• The shorter the focal length, the mores stronger the lens is.
• Ways to make lens more strong

  
  

  - Make lens more curved

  - Use different materials