A Lens is a type of mirror which refracts the light instead of reflection.Refraction is the bending of a light when it enters a medium. Here the medium is Lens.
- Lens are of various types but the two most important types are convex (on Bi-convex) and concave (or Bi-concave) lens
- Convex lens are thicker in middle than the edges whereas concave lens are thinner at the middle than at the edges
- Lenses are transparent and light can pass through them.
- Convex lens are also called convergent as they concentrate (bend inward) the light falling on it.
- Concave lens are also called divergent lens as they expand the light (bend outward) falling on it.
- Real images are formed using convex lens by placing them in between the object and the screen.
- Virtual images are also formed by convex lens which is erect and larger in size.
- Concave lens do not form real images. They only form virtual images which are always erect and smaller in size.
- Applications of lens include magnifying glass, telescopes, contact lens, cameras etc.