Reference Links

Link that connect you can with the history of lens and what all other different types of lenses.
http://en.wikipedia.org/wiki/Lens_(optics)

The link help you to explore the anatomy of convex lens i.e. how a set of prisms acting as a convex lens.
http://www.physicsclassroom.com/class/refrn/Lesson-5/The-Anatomy-of-a-Lens

The link help you to explore some important applications of lenses.
http://www.explainthatstuff.com/lenses.html