A lens can be converging (convex) or diverging (concave). The centre of the lens is called the optical centre C. In a ray diagram, a converging lens is drawn as a vertical line with outward facing ...

A diverging lens is thinner in the middle than ... table below summarises the nature of the images produced by a converging lens. The converging (convex) lens provides the rest of the refraction ...

Just over 400 years ago, Hans Lipperhey filed a patent for an optical device that he (and possibly other Dutch spectacle makers) had invented by putting together a converging and a diverging lens ...